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UberDDR3/rtl/ddr3_controller.v

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////////////////////////////////////////////////////////////////////////////////
//
// Filename: ddr3_controller.v
// {{{
// Project: DDR3 Controller
//
// Purpose: This DDR3 controller was originally designed to be used on the
// Network Switch Project (https://github.com/ZipCPU/eth10g). The Network Switch
// project uses a Kintex 7 FPGA (XC7K160T-3FFG676E).
// The goal will be to:
// - Run this at 1600Mbps (Maximum Physical Interface (PHY) Rate for a 4:1
// memory controller based on "DC and AC Switching Characteristics" for Kintex 7)
// - Parameterize everything
// - Interface should be (nearly) bus agnostic
// - High (sustained) data throughput. Sequential writes should be able to continue without interruption
//
// Engineer: Angelo C. Jacobo
//
////////////////////////////////////////////////////////////////////////////////
// NOTE TO SELF are questions which I still need to answer
// Comments are continuously added on this RTL for better readability
//`define FORMAL_COVER //skip reset sequence during formal verification to fit in cover depth
`default_nettype none
`timescale 1ps / 1ps
//
// speed bin
`define DDR3_1600_11_11_11
//`define DDR3_1333_9_9_9
//`define DDR3_1066_7_7_7
//
//DDR3 Capacity
`define RAM_8Gb
//`define RAM_2Gb
//`define RAM_4Gb
//`define RAM_8Gb
module ddr3_controller #(
parameter integer CONTROLLER_CLK_PERIOD = 10_000, //ps, clock period of the controller interface
DDR3_CLK_PERIOD = 2_500, //ps, clock period of the DDR3 RAM device (must be 1/4 of the CONTROLLER_CLK_PERIOD)
ROW_BITS = 14, //width of DDR3 row address
COL_BITS = 10, //width of DDR3 column address
BA_BITS = 3, //width of bank address
DQ_BITS = 8, //device width
LANES = 2, //number of DDR3 device to be controlled
AUX_WIDTH = 4, //width of aux line (must be >= 4)
WB2_ADDR_BITS = 7, //width of 2nd wishbone address bus
WB2_DATA_BITS = 32, //width of 2nd wishbone data bus
/* verilator lint_off UNUSEDPARAM */
parameter[0:0] MICRON_SIM = 0, //enable faster simulation for micron ddr3 model (shorten POWER_ON_RESET_HIGH and INITIAL_CKE_LOW)
ODELAY_SUPPORTED = 1, //set to 1 when ODELAYE2 is supported
SECOND_WISHBONE = 0, //set to 1 if 2nd wishbone is needed
parameter // The next parameters act more like a localparam (since user does not have to set this manually) but was added here to simplify port declaration
serdes_ratio = 4, // this controller is fixed as a 4:1 memory controller (CONTROLLER_CLK_PERIOD/DDR3_CLK_PERIOD = 4)
wb_data_bits = DQ_BITS*LANES*serdes_ratio*2,
wb_addr_bits = ROW_BITS + COL_BITS + BA_BITS - $clog2(serdes_ratio*2),
wb_sel_bits = wb_data_bits / 8,
wb2_sel_bits = WB2_DATA_BITS / 8,
//4 is the width of a single ddr3 command {cs_n, ras_n, cas_n, we_n} plus 3 (ck_en, odt, reset_n) plus bank bits plus row bits
cmd_len = 4 + 3 + BA_BITS + ROW_BITS,
lanes_clog2 = $clog2(LANES) == 0? 1: $clog2(LANES)
)
(
input wire i_controller_clk, //i_controller_clk has period of CONTROLLER_CLK_PERIOD
(* mark_debug = "true" *) input wire i_rst_n, //200MHz input clock
// Wishbone inputs
input wire i_wb_cyc, //bus cycle active (1 = normal operation, 0 = all ongoing transaction are to be cancelled)
input wire i_wb_stb, //request a transfer
input wire i_wb_we, //write-enable (1 = write, 0 = read)
input wire[wb_addr_bits - 1:0] i_wb_addr, //burst-addressable {row,bank,col}
input wire[wb_data_bits - 1:0] i_wb_data, //write data, for a 4:1 controller data width is 8 times the number of pins on the device
input wire[wb_sel_bits - 1:0] i_wb_sel, //byte strobe for write (1 = write the byte)
input wire[AUX_WIDTH - 1:0] i_aux, //for AXI-interface compatibility (given upon strobe)
// Wishbone outputs
output reg o_wb_stall, //1 = busy, cannot accept requests
output wire o_wb_ack, //1 = read/write request has completed
output wire[wb_data_bits - 1:0] o_wb_data, //read data, for a 4:1 controller data width is 8 times the number of pins on the device
output wire[AUX_WIDTH - 1:0] o_aux, //for AXI-interface compatibility (returned upon ack)
//
// Wishbone 2 (PHY) inputs
input wire i_wb2_cyc, //bus cycle active (1 = normal operation, 0 = all ongoing transaction are to be cancelled)
(* mark_debug = "true" *) input wire i_wb2_stb, //request a transfer
input wire i_wb2_we, //write-enable (1 = write, 0 = read)
input wire[WB2_ADDR_BITS - 1:0] i_wb2_addr, //memory-mapped register to be accessed
input wire[wb2_sel_bits - 1:0] i_wb2_sel, //byte strobe for write (1 = write the byte)
input wire[WB2_DATA_BITS - 1:0] i_wb2_data, //write data
// Wishbone 2 (Controller) outputs
output reg o_wb2_stall, //1 = busy, cannot accept requests
(* mark_debug = "true" *) output reg o_wb2_ack, //1 = read/write request has completed
output reg[WB2_DATA_BITS - 1:0] o_wb2_data, //read data
//
// PHY interface
(* mark_debug = "true" *) input wire[DQ_BITS*LANES*8 - 1:0] i_phy_iserdes_data,
(* mark_debug = "true" *) input wire[LANES*serdes_ratio*2 - 1:0] i_phy_iserdes_dqs,
input wire[LANES*serdes_ratio*2 - 1:0] i_phy_iserdes_bitslip_reference,
(* mark_debug = "true" *) input wire i_phy_idelayctrl_rdy,
output wire[cmd_len*serdes_ratio-1:0] o_phy_cmd,
(* mark_debug = "true" *) output wire o_phy_dqs_tri_control, o_phy_dq_tri_control,
output wire o_phy_toggle_dqs,
(* mark_debug = "true" *) output wire[wb_data_bits-1:0] o_phy_data,
output wire[wb_sel_bits-1:0] o_phy_dm,
output wire[4:0] o_phy_odelay_data_cntvaluein, o_phy_odelay_dqs_cntvaluein,
(* mark_debug = "true" *) output wire[4:0] o_phy_idelay_data_cntvaluein, o_phy_idelay_dqs_cntvaluein,
output reg[LANES-1:0] o_phy_odelay_data_ld, o_phy_odelay_dqs_ld,
output reg[LANES-1:0] o_phy_idelay_data_ld,
(* mark_debug = "true" *) output reg[LANES-1:0] o_phy_idelay_dqs_ld,
output reg[LANES-1:0] o_phy_bitslip,
output reg o_phy_write_leveling_calib,
output wire o_phy_reset,
// Debug port
output wire [31:0] o_debug1,
output wire [31:0] o_debug2,
output wire [31:0] o_debug3
);
/************************************************************* Command Parameters *************************************************************/
//DDR3 commands {cs_n, ras_n, cas_n, we_n} (JEDEC DDR3 doc pg. 33 )
localparam[3:0]CMD_MRS = 4'b0000, // Mode Register Set
CMD_REF = 4'b0001, // Refresh
CMD_PRE = 4'b0010, // Precharge (A10-AP: 0 = Single Bank Precharge, 1 = Precharge All Banks)
CMD_ACT = 4'b0011, // Bank Activate
CMD_WR = 4'b0100, // Write (A10-AP: 0 = no Auto-Precharge) (A12-BC#: 1 = Burst Length 8)
CMD_RD = 4'b0101, //Read (A10-AP: 0 = no Auto-Precharge) (A12-BC#: 1 = Burst Length 8)
CMD_NOP = 4'b0111, // No Operation
CMD_ZQC = 4'b0110; // ZQ Calibration (A10-AP: 0 = ZQ Calibration Short, 1 = ZQ Calibration Long)
localparam RST_DONE = 27, // Command bit that determines if reset seqeunce had aready finished. non-persistent (only needs to be toggled once),
REF_IDLE = 27, // No refresh is about to start and no ongoing refresh. (same bit as RST_DONE)
USE_TIMER = 26, // Command bit that determines if timer will be used (if delay is zero, USE_TIMER must be LOW)
A10_CONTROL = 25, //Command bit that determines if A10 AutoPrecharge will be high
CLOCK_EN = 24, //Clock-enable to DDR3
RESET_N = 23, //Reset_n to DDR3
DDR3_CMD_START = 22, //Start of DDR3 command slot
DDR3_CMD_END = 19, //end of DDR3 command slot
MRS_BANK_START = 18; //start of bank value in MRS value
// ddr3 command partitioning
/* verilator lint_off UNUSEDPARAM */
localparam CMD_CS_N = cmd_len - 1,
CMD_RAS_N = cmd_len - 2,
CMD_CAS_N= cmd_len - 3,
CMD_WE_N = cmd_len - 4,
CMD_ODT = cmd_len - 5,
CMD_CKE = cmd_len - 6,
CMD_RESET_N = cmd_len - 7,
CMD_BANK_START = BA_BITS + ROW_BITS - 1,
CMD_ADDRESS_START = ROW_BITS - 1;
/* verilator lint_on UNUSEDPARAM */
localparam READ_SLOT = get_slot(CMD_RD),
WRITE_SLOT = get_slot(CMD_WR),
ACTIVATE_SLOT = get_slot(CMD_ACT),
PRECHARGE_SLOT = get_slot(CMD_PRE),
REMAINING_SLOT = get_slot(0);
// Data does not have to be delayed (DQS is the on that has to be
// delayed and center-aligned to the center eye of data)
localparam DATA_INITIAL_ODELAY_TAP = 0;
//Posedge of DQS needs to be aligned to the center eye of the data.
//This means DQS needs to be delayed by a quarter of the ddr3
//clk period relative to the data. Subtract by 600ps to include
//the IODELAY insertion delay. Divide by a delay resolution of
//78.125ps per tap to get the needed tap value. Then add the tap
//value used in data to have the delay relative to the data.
localparam DQS_INITIAL_ODELAY_TAP = $rtoi(((DDR3_CLK_PERIOD/4))/78.125 + DATA_INITIAL_ODELAY_TAP);
//Incoming DQS should be 90 degree delayed relative to incoming data
localparam DATA_INITIAL_IDELAY_TAP = 0; //600ps delay
localparam DQS_INITIAL_IDELAY_TAP = $rtoi(((DDR3_CLK_PERIOD/4))/78.125 + DATA_INITIAL_IDELAY_TAP);
/*********************************************************************************************************************************************/
/********************************************************** Timing Parameters ***********************************************************************************/
localparam DELAY_SLOT_WIDTH = 19; //Bitwidth of the delay slot and mode register slot on the reset/refresh rom will be at the same size as the Mode Register
localparam POWER_ON_RESET_HIGH = 200_000_000; // 200_000_000 ps (200 us) reset must be active at initialization
localparam INITIAL_CKE_LOW = 500_000_000; // 500_000_000 ps (500 us) cke must be low before activating
`ifdef DDR3_1600_11_11_11 //DDR3-1600 (11-11-11) speed bin
localparam tRCD = 13_750; // ps Active to Read/Write command time
localparam tRP = 13_750; // ps Precharge command period
localparam tRAS = 35_000; // ps ACT to PRE command period
`elsif DDR3_1333_9_9_9 //DDR3-1333 (9-9-9) speed bin
localparam tRCD = 13_500; // ps Active to Read/Write command time
localparam tRP = 13_500; // ps Precharge command period
localparam tRAS = 36_000; // ps ACT to PRE command period
`elsif DDR3_1066_7_7_7 //DDR3-1066 (7-7-7) speed bin
localparam tRCD = 13_125; // ps Active to Read/Write command time
localparam tRP = 13_125; // ps Precharge command period
localparam tRAS = 37_500; // ps ACT to PRE command period
`else
"Throw an error here if speed bin is not recognized (or not defined)"
`endif
`ifdef RAM_1Gb
localparam tRFC = 110_000; // ps Refresh command to ACT or REF
`elsif RAM_2Gb
localparam tRFC = 160_000; // ps Refresh command to ACT or REF
`elsif RAM_4Gb
localparam tRFC = 300_000; // ps Refresh command to ACT or REF
`elsif RAM_8Gb
localparam tRFC = 350_000; // ps Refresh command to ACT or REF
`else
"Throw an error here if capacity is not recognized (or not defined)"
`endif
localparam tREFI = 7_800_000; //ps Average periodic refresh interval
localparam tXPR = max(5*DDR3_CLK_PERIOD, tRFC+10_000); // ps Exit Reset from CKE HIGH to a valid command
localparam tWR = 15_000; // ps Write Recovery Time
localparam tWTR = max(nCK_to_ps(4), 7_500); //ps Delay from start of internal write transaction to internal read command
localparam tWLMRD = nCK_to_cycles(40); // nCK First DQS/DQS# rising edge after write leveling mode is programmed
localparam tWLO = 9_000; //ps Write leveling output delay
localparam tWLOE = 2_000; //ps Write leveling output error
localparam tRTP = max(nCK_to_ps(4), 7_500); //ps Internal Command to PRECHARGE Command delay
localparam tCCD = 4; //nCK CAS to CAS command delay
/* verilator lint_off WIDTHEXPAND */
localparam tMOD = max(nCK_to_cycles(12), ps_to_cycles(15_000)); //cycles (controller) Mode Register Set command update delay
localparam tZQinit = max(nCK_to_cycles(512), ps_to_cycles(640_000));//cycles (controller) Power-up and RESET calibration time
/* verilator lint_on WIDTHEXPAND */
localparam CL_nCK = CL_generator(DDR3_CLK_PERIOD); //read latency (given in JEDEC DDR3 spec)
localparam CWL_nCK = CWL_generator(DDR3_CLK_PERIOD); //write latency (given in JEDEC DDR3 spec)
localparam DELAY_MAX_VALUE = ps_to_cycles(INITIAL_CKE_LOW); //Largest possible delay needed by the reset and refresh sequence
localparam DELAY_COUNTER_WIDTH= $clog2(DELAY_MAX_VALUE); //Bitwidth needed by the maximum possible delay, this will be the delay counter width
localparam CALIBRATION_DELAY = 2; // must be >= 2
/*********************************************************************************************************************************************/
/********************************************************** Computed Delay Parameters **********************************************************/
/* verilator lint_off WIDTHEXPAND */
localparam[3:0] PRECHARGE_TO_ACTIVATE_DELAY = find_delay(ps_to_nCK(tRP), PRECHARGE_SLOT, ACTIVATE_SLOT); //3
localparam[3:0] ACTIVATE_TO_PRECHARGE_DELAY = find_delay(ps_to_nCK(tRAS), ACTIVATE_SLOT, PRECHARGE_SLOT);
localparam[3:0] ACTIVATE_TO_WRITE_DELAY = find_delay(ps_to_nCK(tRCD), ACTIVATE_SLOT, WRITE_SLOT); //3
localparam[3:0] ACTIVATE_TO_READ_DELAY = find_delay(ps_to_nCK(tRCD), ACTIVATE_SLOT, READ_SLOT); //2
localparam[3:0] READ_TO_WRITE_DELAY = find_delay((CL_nCK + tCCD + 2 - CWL_nCK), READ_SLOT, WRITE_SLOT); //2
localparam[3:0] READ_TO_READ_DELAY = 0;
localparam[3:0] READ_TO_PRECHARGE_DELAY = find_delay(ps_to_nCK(tRTP), READ_SLOT, PRECHARGE_SLOT); //1
localparam[3:0] WRITE_TO_WRITE_DELAY = 0;
localparam[3:0] WRITE_TO_READ_DELAY = find_delay((CWL_nCK + 4 + ps_to_nCK(tWTR)), WRITE_SLOT, READ_SLOT); //4
localparam[3:0] WRITE_TO_PRECHARGE_DELAY = find_delay((CWL_nCK + 4 + ps_to_nCK(tWR)), WRITE_SLOT, PRECHARGE_SLOT); //5
/* verilator lint_on WIDTHEXPAND */
localparam PRE_REFRESH_DELAY = WRITE_TO_PRECHARGE_DELAY + 1;
`ifdef FORMAL
(*keep*) wire[3:0] f_PRECHARGE_TO_ACTIVATE_DELAY, f_ACTIVATE_TO_PRECHARGE_DELAY, f_ACTIVATE_TO_WRITE_DELAY, f_ACTIVATE_TO_READ_DELAY,
f_READ_TO_WRITE_DELAY, f_READ_TO_READ_DELAY, f_READ_TO_PRECHARGE_DELAY, f_WRITE_TO_WRITE_DELAY,
f_WRITE_TO_READ_DELAY, f_WRITE_TO_PRECHARGE_DELAY;
assign f_PRECHARGE_TO_ACTIVATE_DELAY = PRECHARGE_TO_ACTIVATE_DELAY;
assign f_ACTIVATE_TO_PRECHARGE_DELAY = ACTIVATE_TO_PRECHARGE_DELAY;
assign f_ACTIVATE_TO_WRITE_DELAY = ACTIVATE_TO_WRITE_DELAY;
assign f_ACTIVATE_TO_READ_DELAY = ACTIVATE_TO_READ_DELAY;
assign f_READ_TO_WRITE_DELAY = READ_TO_WRITE_DELAY;
assign f_READ_TO_READ_DELAY = READ_TO_READ_DELAY;
assign f_READ_TO_PRECHARGE_DELAY = READ_TO_PRECHARGE_DELAY;
assign f_WRITE_TO_WRITE_DELAY = WRITE_TO_WRITE_DELAY;
assign f_WRITE_TO_READ_DELAY = WRITE_TO_READ_DELAY;
assign f_WRITE_TO_PRECHARGE_DELAY = WRITE_TO_PRECHARGE_DELAY;
`endif
//MARGIN_BEFORE_ANTICIPATE is the number of columns before the column
//end when the anticipate can start
//the worst case scenario is when the anticipated bank needs to be precharged
//thus the margin must satisfy tRP (for precharge) and tRCD (for activate).
//Also, worscase is when the anticipated bank still has the leftover of the
//WRITE_TO_PRECHARGE_DELAY thus consider also this.
localparam MARGIN_BEFORE_ANTICIPATE = PRECHARGE_TO_ACTIVATE_DELAY + ACTIVATE_TO_WRITE_DELAY + WRITE_TO_PRECHARGE_DELAY;
// STAGE2_DATA_DEPTH is the number of controller clk cycles of delay before issuing the data after the write command
// depends on the CWL_nCK
/* verilator lint_off WIDTHEXPAND */
localparam STAGE2_DATA_DEPTH = (CWL_nCK - (3 - WRITE_SLOT + 1))/4 + 1; //this is always >= 1 (5 - (3 - 3 + 1))/4.0 -> floor(1) + 1 = floor(4
/* verilator lint_on WIDTHEXPAND */
`ifdef FORMAL
wire stage2_data_depth;
assign stage2_data_depth = STAGE2_DATA_DEPTH;
always @* begin
assert(STAGE2_DATA_DEPTH-2 >= 0);
end
`endif
localparam READ_DELAY = $rtoi($floor((CL_nCK - (3 - READ_SLOT + 1))/4.0 )); // how many controller clk cycles to satisfy CL_nCK of ddr3_clk cycles
// READ_ACK_PIPE_WIDTH is the delay between read command issued (starting from the controller) until the data is received by the controller
//the delays included the ODELAY and OSERDES when issuing the read command
//and the IDELAY and ISERDES when receiving the data (NOTE TO SELF: ELABORATE ON WHY THOSE MAGIC NUMBERS)
localparam READ_ACK_PIPE_WIDTH = READ_DELAY + 1 + 2 + 1 + 1;
localparam MAX_ADDED_READ_ACK_DELAY = 16;
localparam DELAY_BEFORE_WRITE_LEVEL_FEEDBACK = STAGE2_DATA_DEPTH + ps_to_cycles(tWLO+tWLOE) + 10; //plus 10 controller clocks for possible bus latency and
//the delay for receiving feedback DQ from IOBUF -> IDELAY -> ISERDES
/*********************************************************************************************************************************************/
/********************************************************** Read/Write Calibration Parameters **********************************************************/
localparam IDLE = 0,
BITSLIP_DQS_TRAIN_1 = 1,
MPR_READ = 2,
COLLECT_DQS = 3,
ANALYZE_DQS = 4,
CALIBRATE_DQS = 5,
BITSLIP_DQS_TRAIN_2 = 6,
START_WRITE_LEVEL = 7,
WAIT_FOR_FEEDBACK = 8,
ISSUE_WRITE_1 = 9,
ISSUE_WRITE_2 = 10,
ISSUE_READ = 11,
READ_DATA = 12,
ANALYZE_DATA = 13,
CHECK_STARTING_DATA = 14,
BITSLIP_DQS_TRAIN_3 = 15,
//WRITE_ZERO = 16,
BURST_WRITE = 17,
BURST_READ = 18,
RANDOM_WRITE = 19,
RANDOM_READ = 20,
ALTERNATE_WRITE_READ = 21,
FINISH_READ = 22,
DONE_CALIBRATE = 23;
localparam STORED_DQS_SIZE = 5, //must be >= 2
REPEAT_DQS_ANALYZE = 1,
REPEAT_CLK_SAMPLING = 5; // repeat DQS read to find the accurate starting position of DQS
/*********************************************************************************************************************************************/
/************************************************************* Set Mode Registers Parameters *************************************************************/
// MR2 (JEDEC DDR3 doc pg. 30)
localparam[2:0] PASR = 3'b000; //Partial Array Self-Refresh: Full Array
localparam[3:0] CWL = CWL_nCK-4'd5; //CAS write Latency
localparam[0:0] ASR = 1'b1; //Auto Self-Refresh: on
localparam[0:0] SRT = 1'b0; //Self-Refresh Temperature Range:0 (If ASR = 1, SRT bit must be set to 0)
localparam[1:0] RTT_WR = 2'b00; //Dynamic ODT: off
localparam[2:0] MR2_SEL = 3'b010; //Selected Mode Register
localparam[18:0] MR2 = {MR2_SEL, 5'b00000, RTT_WR, 1'b0, SRT, ASR, CWL[2:0], PASR};
// MR3 (JEDEC DDR3 doc pg. 32)
localparam[1:0] MPR_LOC = 2'b00; //Data location for MPR Reads: Predefined Pattern 0_1_0_1_0_1_0_1
localparam[0:0] MPR_EN = 1'b1; //MPR Enable: Enable MPR reads and calibration during initialization
localparam[2:0] MR3_SEL = 3'b011; //MPR Selected
localparam[18:0] MR3_MPR_EN = {MR3_SEL, 13'b0_0000_0000_0000, MPR_EN, MPR_LOC};
localparam[18:0] MR3_MPR_DIS = {MR3_SEL, 13'b0_0000_0000_0000, !MPR_EN, MPR_LOC};
// MR1 (JEDEC DDR3 doc pg. 27)
localparam DLL_EN = 1'b0; //DLL Enable/Disable: Enabled(0)
localparam[1:0] DIC = 2'b00; //Output Driver Impedance Control
localparam[2:0] RTT_NOM = 3'b011; //RTT Nominal: 40ohms (RQZ/6) is the impedance of the PCB trace
localparam[0:0] WL_EN = 1'b1; //Write Leveling Enable: Disabled
localparam[1:0] AL = 2'b00; //Additive Latency: Disabled
localparam[0:0] TDQS = 1'b0; //Termination Data Strobe: Disabled (provides additional termination resistance outputs.
//When the TDQS function is disabled, the DM function is provided (vice-versa).TDQS function is only
//available for X8 DRAM and must be disabled for X4 and X16.
localparam[0:0] QOFF = 1'b0; //Output Buffer Control: Enabled
localparam[2:0] MR1_SEL = 3'b001; //Selected Mode Register
localparam[18:0] MR1_WL_EN = {MR1_SEL, 3'b000, QOFF, TDQS, 1'b0, RTT_NOM[2], 1'b0, WL_EN, RTT_NOM[1], DIC[1], AL, RTT_NOM[0], DIC[0], DLL_EN};
localparam[18:0] MR1_WL_DIS = {MR1_SEL, 3'b000, QOFF, TDQS, 1'b0, RTT_NOM[2], 1'b0, !WL_EN, RTT_NOM[1], DIC[1], AL, RTT_NOM[0], DIC[0], DLL_EN};
//MR0 (JEDEC DDR3 doc pg. 24)
localparam[1:0] BL = 2'b00; //Burst Length: 8 (Fixed)
localparam[3:0] CL = (CL_nCK-4)*2; //CAS Read Latency
localparam[0:0] RBT = 1'b0; //Read Burst Type: Nibble Sequential
localparam[0:0] DLL_RST = 1'b1; //DLL Reset: Yes (this is self-clearing and must be applied after DLL enable)
localparam[2:0] WR = WRA_mode_register_value($rtoi($ceil(tWR/DDR3_CLK_PERIOD))); //Write recovery for autoprecharge (
localparam[0:0] PPD = 1'b0; //DLL Control for Precharge PD: Slow exit (DLL off)
localparam[2:0] MR0_SEL = 3'b000;
localparam[18:0] MR0 = {MR0_SEL, 3'b000, PPD, WR, DLL_RST, 1'b0, CL[3:1], RBT, CL[0], BL};
/*********************************************************************************************************************************************/
localparam INITIAL_RESET_INSTRUCTION = {5'b01000 , CMD_NOP , { {(DELAY_SLOT_WIDTH-3){1'b0}} , 3'd5} };
/************************************************************* Registers and Wires *************************************************************/
integer index;
(* mark_debug = "true" *) reg[4:0] instruction_address = 0; //address for accessing rom instruction
reg[27:0] instruction = INITIAL_RESET_INSTRUCTION; //instruction retrieved from reset instruction rom
reg[ DELAY_COUNTER_WIDTH - 1:0] delay_counter = INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0]; //counter used for delays
reg delay_counter_is_zero = (INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0] == 0); //counter is now zero so retrieve next delay
reg reset_done = 0; //high if reset has already finished
reg pause_counter = 0;
wire issue_read_command;
reg stage2_update = 1;
reg stage2_stall = 0;
reg stage1_stall = 0;
reg[(1<<BA_BITS)-1:0] bank_status_q, bank_status_d; //bank_status[bank_number]: determine current state of bank (1=active , 0=idle)
//bank_active_row[bank_number] = stores the active row address in the specified bank
reg[ROW_BITS-1:0] bank_active_row_q[(1<<BA_BITS)-1:0], bank_active_row_d[(1<<BA_BITS)-1:0];
//pipeline stage 1 regs
reg stage1_pending = 0;
reg[AUX_WIDTH-1:0] stage1_aux = 0;
reg stage1_we = 0;
reg[wb_data_bits - 1:0] stage1_data = 0;
reg[wb_sel_bits - 1:0] stage1_dm = 0;
reg[COL_BITS-1:0] stage1_col = 0;
reg[BA_BITS-1:0] stage1_bank = 0;
reg[ROW_BITS-1:0] stage1_row = 0;
reg[BA_BITS-1:0] stage1_next_bank = 0;
reg[ROW_BITS-1:0] stage1_next_row = 0;
wire[wb_addr_bits-1:0] wb_addr_plus_anticipate, calib_addr_plus_anticipate;
//pipeline stage 2 regs
reg stage2_pending = 0;
reg[AUX_WIDTH-1:0] stage2_aux = 0;
reg stage2_we = 0;
reg[wb_sel_bits - 1:0] stage2_dm_unaligned = 0, stage2_dm_unaligned_temp = 0;
reg[wb_sel_bits - 1:0] stage2_dm[STAGE2_DATA_DEPTH-1:0];
reg[wb_data_bits - 1:0] stage2_data_unaligned = 0, stage2_data_unaligned_temp = 0;
reg[wb_data_bits - 1:0] stage2_data[STAGE2_DATA_DEPTH-1:0];
reg [DQ_BITS*8 - 1:0] unaligned_data[LANES-1:0];
reg [8 - 1:0] unaligned_dm[LANES-1:0];
reg[COL_BITS-1:0] stage2_col = 0;
reg[BA_BITS-1:0] stage2_bank = 0;
reg[ROW_BITS-1:0] stage2_row = 0;
//delay counter for every banks
reg[3:0] delay_before_precharge_counter_q[(1<<BA_BITS)-1:0], delay_before_precharge_counter_d[(1<<BA_BITS)-1:0]; //delay counters
reg[3:0] delay_before_activate_counter_q[(1<<BA_BITS)-1:0], delay_before_activate_counter_d[(1<<BA_BITS)-1:0] ;
reg[3:0] delay_before_write_counter_q[(1<<BA_BITS)-1:0], delay_before_write_counter_d[(1<<BA_BITS)-1:0] ;
reg[3:0] delay_before_read_counter_q[(1<<BA_BITS)-1:0] , delay_before_read_counter_d[(1<<BA_BITS)-1:0] ;
//commands to be sent to PHY (4 slots per controller clk cycle)
reg[cmd_len-1:0] cmd_d[3:0];
initial begin
o_phy_bitslip = 0;
end
reg cmd_odt_q = 0, cmd_odt, cmd_ck_en, cmd_reset_n;
reg o_wb_stall_q = 1, o_wb_stall_d = 1, o_wb_stall_calib = 1;
reg precharge_slot_busy;
reg activate_slot_busy;
reg[1:0] write_dqs_q;
reg write_dqs_d;
reg[STAGE2_DATA_DEPTH:0] write_dqs;
reg[STAGE2_DATA_DEPTH:0] write_dqs_val;
reg[1:0] write_dq_q;
reg write_dq_d;
reg[STAGE2_DATA_DEPTH+1:0] write_dq;
(* mark_debug = "true" *) reg[$clog2(DONE_CALIBRATE):0] state_calibrate;
reg[STORED_DQS_SIZE*8-1:0] dqs_store = 0;
reg[$clog2(STORED_DQS_SIZE):0] dqs_count_repeat = 0;
reg[$clog2(STORED_DQS_SIZE*8)-1:0] dqs_start_index = 0;
(* mark_debug ="true" *) reg[$clog2(STORED_DQS_SIZE*8)-1:0] dqs_start_index_stored = 0;
(* mark_debug ="true" *) reg[$clog2(STORED_DQS_SIZE*8)-1:0] dqs_target_index = 0;
(* mark_debug ="true" *) reg[$clog2(STORED_DQS_SIZE*8)-1:0] dqs_target_index_orig = 0;
(* mark_debug ="true" *) reg[$clog2(STORED_DQS_SIZE*8):0] dq_target_index[LANES-1:0];
(* mark_debug ="true" *) wire[$clog2(STORED_DQS_SIZE*8)-1:0] dqs_target_index_value;
reg[$clog2(REPEAT_DQS_ANALYZE):0] dqs_start_index_repeat=0;
reg[3:0] train_delay;
(* mark_debug = "true" *) reg[3:0] delay_before_read_data = 0;
reg[$clog2(DELAY_BEFORE_WRITE_LEVEL_FEEDBACK):0] delay_before_write_level_feedback = 0;
reg initial_dqs = 0;
(* mark_debug = "true" *) reg[lanes_clog2-1:0] lane = 0;
reg[$clog2(8*LANES)-1:0] lane_times_8 = 0;
/* verilator lint_off UNUSEDSIGNAL */
reg[15:0] dqs_bitslip_arrangement = 0;
/* verilator lint_off UNUSEDSIGNAL */
(* mark_debug = "true" *) reg[3:0] added_read_pipe_max = 0;
(* mark_debug = "true" *) reg[3:0] added_read_pipe[LANES - 1:0];
//each lane will have added delay relative to when ISERDES should actually return the data
//this make sure that we will wait until the lane with longest delay (added_read_pipe_max) is received before
//all lanes are sent to wishbone data
//contains the ack shift reg for both read and write
reg[AUX_WIDTH:0] shift_reg_read_pipe_q[READ_ACK_PIPE_WIDTH-1:0];
reg[AUX_WIDTH:0] shift_reg_read_pipe_d[READ_ACK_PIPE_WIDTH-1:0]; //issue ack and AUX value , 1=issue command delay (OSERDES delay), 2 = ISERDES delay
reg index_read_pipe; //tells which delay_read_pipe will be updated (there are two delay_read_pipe)
reg index_wb_data; //tells which o_wb_data_q will be sent to o_wb_data
reg[15:0] delay_read_pipe[1:0]; //delay when each lane will retrieve i_phy_iserdes_data (since different lanes might not be aligned with each other and needs to be retrieved at a different time)
reg[wb_data_bits - 1:0] o_wb_data_q[1:0]; //store data retrieved from i_phy_iserdes_data to be sent to o_wb_data
reg[AUX_WIDTH:0] o_wb_ack_read_q[MAX_ADDED_READ_ACK_DELAY-1:0];
reg calib_stb = 0;
reg[wb_sel_bits-1:0] calib_sel = 0;
reg[AUX_WIDTH-1:0] calib_aux = 0;
reg calib_we = 0;
reg[wb_addr_bits-1:0] calib_addr = 0;
reg[wb_data_bits-1:0] calib_data = 0;
reg write_calib_odt = 0;
reg write_calib_dqs = 0;
reg write_calib_dq = 0;
reg prev_write_level_feedback = 1;
reg[wb_data_bits-1:0] read_data_store = 0;
reg[127:0] write_pattern = 0;
(* mark_debug = "true" *) reg[$clog2(64):0] data_start_index[LANES-1:0];
reg[4:0] odelay_data_cntvaluein[LANES-1:0];
reg[4:0] odelay_dqs_cntvaluein[LANES-1:0];
reg[4:0] idelay_data_cntvaluein[LANES-1:0];
reg[4:0] idelay_data_cntvaluein_prev;
reg[4:0] idelay_dqs_cntvaluein[LANES-1:0];
reg[$clog2(REPEAT_CLK_SAMPLING):0] sample_clk_repeat = 0;
reg stored_write_level_feedback = 0;
reg[5:0] start_index_check = 0;
reg[63:0] read_lane_data = 0;
reg odelay_cntvalue_repeated = 0;
reg already_finished_calibration = 0;
// Wishbone 2
reg wb2_stb = 0;
reg wb2_update = 0;
reg wb2_we = 0;
reg[WB2_ADDR_BITS-1:0] wb2_addr = 0;
reg[WB2_DATA_BITS-1:0] wb2_data = 0;
reg[wb2_sel_bits-1:0] wb2_sel = 0;
reg[4:0] wb2_phy_odelay_data_cntvaluein;
reg[4:0] wb2_phy_odelay_dqs_cntvaluein;
reg[4:0] wb2_phy_idelay_data_cntvaluein;
reg[4:0] wb2_phy_idelay_dqs_cntvaluein;
reg[LANES-1:0] wb2_phy_odelay_data_ld;
reg[LANES-1:0] wb2_phy_odelay_dqs_ld;
reg[LANES-1:0] wb2_phy_idelay_data_ld;
reg[LANES-1:0] wb2_phy_idelay_dqs_ld;
reg[LANES-1:0] write_level_fail = 0;
reg[lanes_clog2-1:0] wb2_write_lane;
reg sync_rst_wb2 = 0, sync_rst_controller = 0;
reg reset_from_wb2 = 0, reset_from_calibrate = 0, reset_from_test = 0, repeat_test = 0;
// test calibration
reg[wb_addr_bits-1:0] read_test_address_counter = 0, check_test_address_counter = 0; ////////////////////////////////////////////////////////
reg[31:0] write_test_address_counter = 0;
reg[31:0] correct_read_data = 0, wrong_read_data = 0;
// initial block for all regs
initial begin
o_wb_stall = 1;
for(index = 0; index < MAX_ADDED_READ_ACK_DELAY; index = index + 1) begin
o_wb_ack_read_q[index] = 0;
end
for(index=0; index < (1<<BA_BITS); index=index+1) begin
bank_status_q[index] = 0;
bank_status_d[index] = 0;
bank_active_row_q[index] = 0;
bank_active_row_d[index] = 0;
end
for(index = 0; index < STAGE2_DATA_DEPTH; index = index+1) begin
stage2_data[index] = 0;
stage2_dm[index] = 0;
end
for(index=0; index <(1<<BA_BITS); index=index+1) begin
delay_before_precharge_counter_q[index] = 0;
delay_before_activate_counter_q[index] = 0;
delay_before_write_counter_q[index] = 0;
delay_before_read_counter_q[index] = 0;
end
for(index = 0; index < READ_ACK_PIPE_WIDTH; index = index + 1) begin
shift_reg_read_pipe_q[index] = 0;
shift_reg_read_pipe_d[index] = 0;
end
//set all commands to all 1's makig CS_n high (thus commands are initially NOP)
for(index=0; index < 4; index=index+1) begin
cmd_d[index] = -1;
end
for(index = 0; index < LANES; index = index + 1) begin
odelay_data_cntvaluein[index] = DATA_INITIAL_ODELAY_TAP[4:0];
odelay_dqs_cntvaluein[index] = DQS_INITIAL_ODELAY_TAP[4:0];
idelay_data_cntvaluein[index] = DATA_INITIAL_IDELAY_TAP[4:0];
idelay_dqs_cntvaluein[index] = DQS_INITIAL_IDELAY_TAP[4:0];
dq_target_index[index] = 0;
end
end
/*********************************************************************************************************************************************/
/******************************************* Reset Sequence (JEDEC DDR3 doc pg. 19) *******************************************/
// This reset and refresh sequence logic is designed for simplicity. This uses a Read-Only Memory (ROM))
// to store the commands and time delay. A constant function is used store instructions instead of registers
// to ensure that ROM wil not change values during formal verification induction.
// This idea is sourced from https://zipcpu.com/formal/2019/11/18/genuctrlr.html
// Instruction format:
// RST_DONE/REF_IDLE = 27; //RST_DONE = non-persistent, only needs to be toggled once, command bit that determines if reset seqeunce had aready finished
//REF_IDLE = No refresh is about to start and no ongoing refresh.
// USE_TIMER = 26; // Command bit that determines if timer will be used (if delay is zero, USE_TIMER must be LOW)
// A10_CONTROL = 25, //Command bit that determines if A10 Precharge All Bank will be high
// CLOCK_EN = 24; //Clock-enable to DDR3
// RESET_N = 23; //Reset_n to DDR3
// DDR3_CMD = 22:19
// Timer-Delay or MRS = 18:0 //timer delay and MRS shares same slot, thus MRS commands cannot have delays
// NOTE: The timer delay is a delay in clock cycles AFTER EXECUTING COMMAND, not the ACTUAL CYCLES of the command
// (delay of 1 means 2 clock cycles of command execution) //initial reset instruction has low rst_n, low cke, and has delay of 5
function [27:0] read_rom_instruction(input[4:0] func_instruction_address); begin
case(func_instruction_address)
5'd0:
if (MICRON_SIM)
read_rom_instruction = {5'b01000 , CMD_NOP , ps_to_cycles(POWER_ON_RESET_HIGH/500)};
else
read_rom_instruction = {5'b01000 , CMD_NOP , ps_to_cycles(POWER_ON_RESET_HIGH)};
//0. RESET# needs to be maintained low for minimum 200us with power-up initialization. CKE is pulled
//“Low” anytime before RESET# being de-asserted (min. time 10 ns). .
5'd1:
if (MICRON_SIM)
read_rom_instruction = {5'b01001 , CMD_NOP, ps_to_cycles(INITIAL_CKE_LOW/500)};
else
read_rom_instruction = {5'b01001 , CMD_NOP, ps_to_cycles(INITIAL_CKE_LOW)};
//1. After RESET# is de-asserted, wait for another 500 us until CKE becomes active. During this time, the
//DRAM will start internal state initialization; this will be done independently of external clocks.
// .... Also, a NOP or Deselect command must be registered (with tIS set up time to clock) before
//CKE goes active.
5'd2: read_rom_instruction = {5'b01011 , CMD_NOP, ps_to_cycles(tXPR)};
//2. After CKE is being registered high, wait minimum of Reset CKE Exit time, tXPR.
5'd3: read_rom_instruction = {{2'b00,MR2[10], 2'b11}, CMD_MRS, MR2};
//3. Issue MRS command to load MR2.
5'd4: read_rom_instruction = {{2'b00,MR3_MPR_DIS[10], 2'b11}, CMD_MRS, MR3_MPR_DIS};
//4. All banks must first be in the idle state (all banks precharged and tRP met) before doing MPR calibration, thus issue first disabled MR3
5'd5: read_rom_instruction = {{2'b00,MR1_WL_DIS[10], 2'b11}, CMD_MRS, MR1_WL_DIS};
//5. Issue MRS command to load MR1, enable DLL,and disable WL.
5'd6: read_rom_instruction = {{2'b00,MR0[10], 2'b11}, CMD_MRS, MR0};
//6. Issue MRS command to load MR0 and reset DLL.
5'd7: read_rom_instruction = {5'b01011, CMD_NOP, tMOD[DELAY_SLOT_WIDTH-1:0]};
//7. Delay of tMOD between MRS command to a non-MRS command excluding NOP and DES
5'd8: read_rom_instruction = {5'b01111, CMD_ZQC, tZQinit[DELAY_SLOT_WIDTH-1:0]};
//8. ZQ Calibration command is used to calibrate DRAM Ron & ODT values. ZQCL command triggers the calibration engine
//inside the DRAM and, once calibration is achieved, the calibrated values area transferred from the calibration engine to
//DRAM IO, which gets reflected as updated output driver
// Precharge all banks before enabling MPR
5'd9: read_rom_instruction = {5'b01111, CMD_PRE, ps_to_cycles(tRP)};
//9. All banks must be precharged (A10-AP = high) and idle for a minimum of the precharge time tRP(min) before the Refresh Command can be applied.
5'd10: read_rom_instruction = {{2'b00,MR3_MPR_EN[10], 2'b11}, CMD_MRS, MR3_MPR_EN};
//10. Issue MRS command to load MR3. Prior to enabling the MPR for read calibration, all banks must be in the idle state (all banks
// precharged and tRP met). Once the MPR is enabled, any subsequent RD or RDA commands will be redirected to the MultiPurpose Register.
5'd11: read_rom_instruction = {5'b01011, CMD_NOP, tMOD[DELAY_SLOT_WIDTH-1:0]};
//11. Delay of tMOD between MRS command to a non-MRS command excluding NOP and DES
5'd12: read_rom_instruction = {5'b01011, CMD_NOP, CALIBRATION_DELAY[DELAY_SLOT_WIDTH-1:0]};
//12. Delay for read calibration
5'd13: read_rom_instruction = {{2'b00,MR3_MPR_DIS[10], 2'b11}, CMD_MRS, MR3_MPR_DIS};
//13. Disable MPR after read calibration
5'd14: read_rom_instruction = {{2'b00,MR1_WL_EN[10], 2'b11}, CMD_MRS, MR1_WL_EN};
//14. Issue MRS command to load MR1, and enable WL.
5'd15: read_rom_instruction = {5'b01011, CMD_NOP, tWLMRD[DELAY_SLOT_WIDTH-1:0]};
//15. Delay of tMOD between MRS command to a non-MRS command excluding NOP and DES
5'd16: read_rom_instruction = {5'b01011, CMD_NOP, CALIBRATION_DELAY[DELAY_SLOT_WIDTH-1:0]};
//16. Delay for write calibration
5'd17: read_rom_instruction = {{2'b00,MR1_WL_DIS[10], 2'b11}, CMD_MRS, MR1_WL_DIS};
//17. Issue MRS command to load MR1, and disable WL.
5'd18: read_rom_instruction = {5'b01011, CMD_NOP, tMOD[DELAY_SLOT_WIDTH-1:0]};
//18. Delay of tMOD between MRS command to a non-MRS command excluding NOP and DES
// Perform first refresh and any subsequent refresh (so instruction 12 to 15 will be re-used for the refresh sequence)
5'd19: read_rom_instruction = {5'b01111, CMD_PRE, ps_to_cycles(tRP)};
//19. All banks must be precharged (A10-AP = high) and idle for a minimum of the precharge time tRP(min) before the Refresh Command can be applied.
5'd20: read_rom_instruction = {5'b01011, CMD_REF, ps_to_cycles(tRFC)};
//20. A delay between the Refresh Command and the next valid command, except NOP or DES, must be greater than or equal to the minimum
//Refresh cycle time tRFC(min)
5'd21: read_rom_instruction = {5'b11011, CMD_NOP, ps_to_cycles(tREFI)};
//21. Reset ends now. The refresh interval also starts to count.
5'd22: read_rom_instruction = {5'b01011, CMD_NOP, PRE_REFRESH_DELAY[DELAY_SLOT_WIDTH-1:0]};
// 22. Extra delay needed before starting the refresh sequence.
// (this already sets the wishbone stall high to make sure no user request is on-going when refresh seqeunce starts)
default: read_rom_instruction = {5'b00011, CMD_NOP, {(DELAY_SLOT_WIDTH){1'b0}}};
endcase
end
endfunction
/*********************************************************************************************************************************************/
/******************************************* Reset Sequence ROM Controller *******************************************/
always @(posedge i_controller_clk) begin
sync_rst_controller <= !i_rst_n || reset_from_wb2 || reset_from_calibrate || reset_from_test;
sync_rst_wb2 <= !i_rst_n;
end
assign o_phy_reset = sync_rst_controller;
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
instruction_address <= 0;
`ifdef FORMAL_COVER
instruction_address <= 21;
`endif
instruction <= INITIAL_RESET_INSTRUCTION;
delay_counter <= INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0];
delay_counter_is_zero <= (INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0] == 0);
reset_done <= 1'b0;
end
else begin
//update counter after reaching zero
if(delay_counter_is_zero) begin
delay_counter <= instruction[DELAY_COUNTER_WIDTH - 1:0]; //retrieve delay value of current instruction, we count to zero thus minus 1
end
//else: decrement delay counter when current instruction needs delay
//don't decrement (has infinite time) when last bit of
//delay_counter is 1 (for r/w calibration and prestall delay)
//address will only move forward for these kinds of delay only
//when skip_reset_seq_delay is toggled
else if(instruction[USE_TIMER] /*&& delay_counter != {(DELAY_COUNTER_WIDTH){1'b1}}*/ && !pause_counter) delay_counter <= delay_counter - 1;
//delay_counter of 1 means we will need to update the delay_counter next clock cycle (delay_counter of zero) so we need to retrieve
//now the next instruction. The same thing needs to be done when current instruction does not need the timer delay.
if(delay_counter == 1 || !instruction[USE_TIMER]/* || skip_reset_seq_delay*/) begin
delay_counter_is_zero <= 1;
instruction <= read_rom_instruction(instruction_address);
instruction_address <= (instruction_address == 5'd22)? 5'd19:instruction_address+1; //wrap back of address to repeat refresh sequence
end
//we are now on the middle of a delay
else delay_counter_is_zero <=0;
//instruction[RST_DONE] is non-persistent thus we need to register it once it goes high
reset_done <= instruction[RST_DONE]? 1'b1:reset_done;
end
end
/*********************************************************************************************************************************************/
/******************************************************* Track Bank Status and Issue Command *******************************************************/
//process request transaction
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
o_wb_stall <= 1'b1;
o_wb_stall_q <= 1'b1;
o_wb_stall_calib <= 1'b1;
//set stage 1 to 0
stage1_pending <= 0;
stage1_aux <= 0;
stage1_we <= 0;
stage1_dm <= 0;
stage1_col <= 0;
stage1_bank <= 0;
stage1_row <= 0;
stage1_next_bank <= 0;
stage1_next_row <= 0;
stage1_data <= 0;
//set stage2 to 0
stage2_pending <= 0;
stage2_aux <= 0;
stage2_we <= 0;
stage2_col <= 0;
stage2_bank <= 0;
stage2_row <= 0;
cmd_odt_q <= 0;
stage2_data_unaligned <= 0;
stage2_data_unaligned_temp <= 0;
stage2_dm_unaligned <= 0;
stage2_dm_unaligned_temp <= 0;
for(index=0; index<LANES; index=index+1) begin
unaligned_data[index] <= 0;
unaligned_dm[index] <= 0;
end
//set delay counters to 0
for(index=0; index<(1<<BA_BITS); index=index+1) begin
delay_before_precharge_counter_q[index] <= 0;
delay_before_activate_counter_q[index] <= 0;
delay_before_write_counter_q[index] <= 0;
delay_before_read_counter_q[index] <= 0;
end
//reset bank status and active row
for( index=0; index < (1<<BA_BITS); index=index+1) begin
bank_status_q[index] <= 0;
bank_active_row_q[index] <= 0;
end
//reset data
for(index = 0; index < STAGE2_DATA_DEPTH; index = index+1) begin
stage2_data[index] <= 0;
stage2_dm[index] <= 0;
end
end
// can only start accepting requests when reset is done
else if(reset_done) begin
o_wb_stall <= o_wb_stall_d || state_calibrate != DONE_CALIBRATE;
o_wb_stall_q <= o_wb_stall_d;
o_wb_stall_calib <= o_wb_stall_d; //wb stall for calibration stage
cmd_odt_q <= cmd_odt;
//update delay counter
for(index=0; index< (1<<BA_BITS); index=index+1) begin
delay_before_precharge_counter_q[index] <= delay_before_precharge_counter_d[index];
delay_before_activate_counter_q[index] <= delay_before_activate_counter_d[index];
delay_before_write_counter_q[index] <= delay_before_write_counter_d[index];
delay_before_read_counter_q[index] <= delay_before_read_counter_d[index];
end
//update bank status and active row
for(index=0; index < (1<<BA_BITS); index=index+1) begin
bank_status_q[index] <= bank_status_d[index];
bank_active_row_q[index] <= bank_active_row_d[index];
end
if(instruction_address == 20) begin ///current instruction at precharge
cmd_odt_q <= 1'b0;
//all banks will be in idle after refresh
for( index=0; index < (1<<BA_BITS); index=index+1) begin
bank_status_q[index] <= 0;
end
end
//refresh sequence is on-going
if(!instruction[REF_IDLE]) begin
//no transaction will be pending during refresh
o_wb_stall <= 1'b1;
o_wb_stall_calib <= 1'b1;
end
//if pipeline is not stalled (or a request is left on the prestall
//delay address 19 or if in calib), move pipeline to stage 2
if(!o_wb_stall_q && stage2_update) begin //ITS POSSIBLE ONLY NEXT CLK WILL STALL SUPPOSE TO GO LOW
stage1_pending <= 1'b0; //no request initially unless overridden by the actual stb request
stage2_pending <= stage1_pending;
stage2_aux <= stage1_aux;
stage2_we <= stage1_we;
stage2_col <= stage1_col;
stage2_bank <= stage1_bank;
stage2_row <= stage1_row;
if(ODELAY_SUPPORTED) begin
stage2_data_unaligned <= stage1_data;
stage2_dm_unaligned <= ~stage1_dm; //inverse each bit (1 must mean "masked" or not written)
end
else begin
stage2_data_unaligned_temp <= stage1_data;
stage2_dm_unaligned_temp <= ~stage1_dm; //inverse each bit (1 must mean "masked" or not written)
end
//stage2_data -> shiftreg(CWL) -> OSERDES(DDR) -> ODELAY -> RAM
end
if(!ODELAY_SUPPORTED) begin
stage2_data_unaligned <= stage2_data_unaligned_temp; //_temp is for added delay of 1 clock cycle (no ODELAY so no added delay)
stage2_dm_unaligned <= stage2_dm_unaligned_temp; //_temp is for added delay of 1 clock cycle (no ODELAY so no added delay)
end
// when not in refresh, transaction can only be processed when i_wb_cyc is high and not stall
if(i_wb_cyc && !o_wb_stall) begin
//stage1 will not do the request (pending low) when the
//request is on the same bank as the current request. This
//will ensure stage1 bank will be different from stage2 bank
stage1_pending <= i_wb_stb;//actual request flag
stage1_aux <= i_aux; //aux ID for AXI compatibility
stage1_we <= i_wb_we; //write-enable
stage1_dm <= i_wb_sel; //byte selection
stage1_col <= { i_wb_addr[(COL_BITS- $clog2(serdes_ratio*2)-1):0], {{$clog2(serdes_ratio*2)}{1'b0}} }; //column address (n-burst word-aligned)
stage1_bank <= i_wb_addr[(BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (COL_BITS- $clog2(serdes_ratio*2))]; //bank_address
stage1_row <= i_wb_addr[ (ROW_BITS + BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (BA_BITS + COL_BITS- $clog2(serdes_ratio*2)) ]; //row_address
//stage1_next_bank will not increment unless stage1_next_col
//overwraps due to MARGIN_BEFORE_ANTICIPATE. Thus, anticipated
//precharge and activate will happen only at the end of the
//current column with a margin dictated by
//MARGIN_BEFORE_ANTICIPATE
/* verilator lint_off WIDTH */
{stage1_next_row , stage1_next_bank} <= wb_addr_plus_anticipate >> (COL_BITS- $clog2(serdes_ratio*2));
//anticipated next row and bank to be accessed
/* verilator lint_on WIDTH */
stage1_data <= i_wb_data;
end
// request from calibrate FSM will be accepted here
else if(state_calibrate != DONE_CALIBRATE && !o_wb_stall_calib) begin
stage1_pending <= calib_stb;//actual request flag
stage1_we <= calib_we; //write-enable
stage1_dm <= calib_sel;
stage1_aux <= calib_aux; //aux ID for AXI compatibility
stage1_col <= { calib_addr[(COL_BITS- $clog2(serdes_ratio*2)-1):0], {{$clog2(serdes_ratio*2)}{1'b0}} }; //column address (n-burst word-aligned)
stage1_bank <= calib_addr[(BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (COL_BITS- $clog2(serdes_ratio*2))]; //bank_address
stage1_row <= calib_addr[ (ROW_BITS + BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (BA_BITS + COL_BITS- $clog2(serdes_ratio*2)) ]; //row_address
/* verilator lint_off WIDTH */
{stage1_next_row , stage1_next_bank} <= calib_addr_plus_anticipate >> (COL_BITS- $clog2(serdes_ratio*2));
/* verilator lint_on WIDTH */
stage1_data <= calib_data;
end
for(index = 0; index < LANES; index = index + 1) begin
/* verilator lint_off WIDTH */
// stage2_data_unaligned is the DQ_BITS*LANES*8 raw data from stage 1 so not yet aligned
// unaligned_data is 64 bits
{unaligned_data[index], {
stage2_data[0][((DQ_BITS*LANES)*7 + 8*index) +: 8], stage2_data[0][((DQ_BITS*LANES)*6 + 8*index) +: 8],
stage2_data[0][((DQ_BITS*LANES)*5 + 8*index) +: 8], stage2_data[0][((DQ_BITS*LANES)*4 + 8*index) +: 8],
stage2_data[0][((DQ_BITS*LANES)*3 + 8*index) +: 8], stage2_data[0][((DQ_BITS*LANES)*2 + 8*index) +: 8],
stage2_data[0][((DQ_BITS*LANES)*1 + 8*index) +: 8], stage2_data[0][((DQ_BITS*LANES)*0 + 8*index) +: 8] }}
<= ( { stage2_data_unaligned[((DQ_BITS*LANES)*7 + 8*index) +: 8], stage2_data_unaligned[((DQ_BITS*LANES)*6 + 8*index) +: 8],
stage2_data_unaligned[((DQ_BITS*LANES)*5 + 8*index) +: 8], stage2_data_unaligned[((DQ_BITS*LANES)*4 + 8*index) +: 8],
stage2_data_unaligned[((DQ_BITS*LANES)*3 + 8*index) +: 8], stage2_data_unaligned[((DQ_BITS*LANES)*2 + 8*index) +: 8],
stage2_data_unaligned[((DQ_BITS*LANES)*1 + 8*index) +: 8], stage2_data_unaligned[((DQ_BITS*LANES)*0 + 8*index) +: 8] }
<< data_start_index[index]) | unaligned_data[index];
/*
// Example with LANE 0:
// Burst_0 to burst_7 of unaligned LANE 0 will be extracted which will be shifted by data_start_index.
// Each 8 bits of shift means a burst will be moved to next ddr3_clk cycle, this is needed if for example
// the DQ trace is longer than the command trace where the DQ bits must be delayed by 1 ddr3_clk cycle
// to align the DQ data to the write command.
//
// Since 1 controller clk cycle will have 4 ddr3_clk cycle, and each ddr3_clk cycle is DDR:
// CONTROLLER CLK CYCLE 0: [burst0,burst1] [burst2,burst3] [burst4,burst5] [burst6,burst7]
// CONTROLLER CLK CYCLE 1: [burst0,burst1] [burst2,burst3] [burst4,burst5] [burst6,burst7]
// CONTROLLER CLK CYCLE 2: [burst0,burst1] [burst2,burst3] [burst4,burst5] [burst6,burst7]
//
// shifting by 1 burst means burst 7 will be sent on next controller clk cycle and EVERY BURST WILL SHIFT:
// CONTROLLER CLK CYCLE 0: [xxxxxx,xxxxxx] [burst0,burst1] [burst2,burst3] [burst4,burst5]
// CONTROLLER CLK CYCLE 1: [burst6,burst7] [burst0,burst1] [burst2,burst3] [burst4,burst5]
// CONTROLLER CLK CYCLE 2: [burst6,burst7] [burst0,burst1] [burst2,burst3] [burst4,burst5]
//
// the [burst6,burst7] which has to be stored and delayed until next clk cycle will be handled by unaligned_data
{unaligned_data[0], {
stage2_data[0][((64)*7 + 8*0) +: 8], stage2_data[0][((64)*6 + 8*0) +: 8],
stage2_data[0][((64)*5 + 8*0) +: 8], stage2_data[0][((64)*4 + 8*0) +: 8],
stage2_data[0][((64)*3 + 8*0) +: 8], stage2_data[0][((64)*2 + 8*0) +: 8],
stage2_data[0][((64)*1 + 8*0) +: 8], stage2_data[0][((64)*0 + 8*0) +: 8] }}
<= ( { stage2_data_unaligned[((64)*7 + 8*0) +: 8], stage2_data_unaligned[((64)*6 + 8*0) +: 8],
stage2_data_unaligned[((64)*5 + 8*0) +: 8], stage2_data_unaligned[((64)*4 + 8*0) +: 8],
stage2_data_unaligned[((64)*3 + 8*0) +: 8], stage2_data_unaligned[((64)*2 + 8*0) +: 8],
stage2_data_unaligned[((64)*1 + 8*0) +: 8], stage2_data_unaligned[((64)*0 + 8*0) +: 8] }
<< data_start_index[0]) | unaligned_data[0];
*/
// The same alignment logic is done with data mask
{unaligned_dm[index], {
stage2_dm[0][LANES*7 + index], stage2_dm[0][LANES*6 + index],
stage2_dm[0][LANES*5 + index], stage2_dm[0][LANES*4 + index],
stage2_dm[0][LANES*3 + index], stage2_dm[0][LANES*2 + index],
stage2_dm[0][LANES*1 + index], stage2_dm[0][LANES*0 + index] }}
<= ( { stage2_dm_unaligned[LANES*7 + index], stage2_dm_unaligned[LANES*6 + index],
stage2_dm_unaligned[LANES*5 + index], stage2_dm_unaligned[LANES*4 + index],
stage2_dm_unaligned[LANES*3 + index], stage2_dm_unaligned[LANES*2 + index],
stage2_dm_unaligned[LANES*1 + index], stage2_dm_unaligned[LANES*0 + index] }
<< (data_start_index[index]>>3)) | unaligned_dm[index];
/* verilator lint_on WIDTH */
end
// stage2 can have multiple pipelined stages inside it which acts as delay before issuing the write data (after issuing write command)
for(index = 0; index < STAGE2_DATA_DEPTH-1; index = index+1) begin
stage2_data[index+1] <= stage2_data[index];
stage2_dm[index+1] <= stage2_dm[index];
end
//abort any outgoing ack when cyc is low
if(!i_wb_cyc && state_calibrate == DONE_CALIBRATE) begin
stage2_pending <= 0;
stage1_pending <= 0;
end
end
end
assign o_phy_data = stage2_data[STAGE2_DATA_DEPTH-1]; // the data sent to PHY is the last stage of of stage 2 (since stage 2 can have multiple pipelined stages inside it_
assign o_phy_dm = stage2_dm[STAGE2_DATA_DEPTH-1];
/* verilator lint_off WIDTH */
assign wb_addr_plus_anticipate = i_wb_addr + MARGIN_BEFORE_ANTICIPATE; // wb_addr_plus_anticipate determines if it is near the end of column by checking if it jumps to next row
assign calib_addr_plus_anticipate = calib_addr + MARGIN_BEFORE_ANTICIPATE; // just same as wb_addr_plus_anticipate but while doing calibration
/* verilator lint_on WIDTH */
// DIAGRAM FOR ALL RELEVANT TIMING PARAMETERS:
//
// tRTP
// -------------------------------------------------------------
// | tCCD |
// | -----> Read ---------> Read
// v | ^ |
// Precharge ------> Activate -------->| | tWTR | tRTW
// ^ tRP tRCD | | v
// | ------> Write -------> Write
// | tCCD |
// -------------------------------------------------------------
// tWR (after data burst)
//note: all delays after write counts only after the data burst (except for write-to-write tCCD)
//
//Pipeline Stages:
// wishbone inputs --> stage1 --> stage2 --> cmd
always @* begin
cmd_odt = cmd_odt_q || write_calib_odt;
cmd_ck_en = instruction[CLOCK_EN];
cmd_reset_n = instruction[RESET_N];
stage1_stall = 1'b0;
stage2_stall = 1'b0;
stage2_update = 1'b1; //always update stage 2 UNLESS it has a pending request (stage2_pending high)
o_wb_stall_d = 1'b0; //wb_stall going high is determined on stage 1 (higher priority), wb_stall going low is determined at stage2 (lower priority)
precharge_slot_busy = 0; //flag that determines if stage 2 is issuing precharge (thus stage 1 cannot issue precharge)
activate_slot_busy = 0; //flag that determines if stage 2 is issuing activate (thus stage 1 cannot issue activate)
write_dqs_d = write_calib_dqs;
write_dq_d = write_calib_dq;
for(index=0; index < (1<<BA_BITS); index=index+1) begin
bank_status_d[index] = bank_status_q[index];
bank_active_row_d[index] = bank_active_row_q[index];
end
//set PRECHARGE_SLOT as reset instruction, the remainings are NOP (MSB is high)
//delay_counter_is_zero high signifies start of new reset instruction (the time when the command must be issued)
cmd_d[PRECHARGE_SLOT] = {(!delay_counter_is_zero), instruction[DDR3_CMD_START-1:DDR3_CMD_END] | {3{(!delay_counter_is_zero)}} , cmd_odt, instruction[CLOCK_EN], instruction[RESET_N],
instruction[MRS_BANK_START:(MRS_BANK_START-BA_BITS+1)], instruction[ROW_BITS-1:0]};
cmd_d[PRECHARGE_SLOT][10] = instruction[A10_CONTROL];
cmd_d[READ_SLOT] = {(!issue_read_command), CMD_RD[2:0] | {3{(!issue_read_command)}}, cmd_odt, cmd_ck_en, cmd_reset_n, {(ROW_BITS+BA_BITS){1'b0}}}; // issued during MPR reads (address does not matter)
cmd_d[ACTIVATE_SLOT] = {1'b0, 3'b111 , cmd_odt, cmd_ck_en, cmd_reset_n, {(ROW_BITS+BA_BITS){1'b0}}}; // always NOP by default
// extra slot is created when READ and WRITE slots are the same
// this remaining slot should be NOP by default
if(WRITE_SLOT == READ_SLOT) begin
cmd_d[REMAINING_SLOT] = {1'b0, 3'b111 , cmd_odt, cmd_ck_en, cmd_reset_n, {(ROW_BITS+BA_BITS){1'b0}}}; // always NOP by default
end
// if read and write slot is not shared, the write slot should be NOP by default
else begin
cmd_d[WRITE_SLOT] = {1'b0, 3'b111, cmd_odt, cmd_ck_en, cmd_reset_n, {(ROW_BITS+BA_BITS){1'b0}}}; // always NOP by default
end
// decrement delay counters for every bank , stay to 0 once 0 is reached
// every bank will have its own delay counters for precharge, activate, write, and read
for(index=0; index< (1<<BA_BITS); index=index+1) begin
delay_before_precharge_counter_d[index] = (delay_before_precharge_counter_q[index] == 0)? 0: delay_before_precharge_counter_q[index] - 1;
delay_before_activate_counter_d[index] = (delay_before_activate_counter_q[index] == 0)? 0: delay_before_activate_counter_q[index] - 1;
delay_before_write_counter_d[index] = (delay_before_write_counter_q[index] == 0)? 0:delay_before_write_counter_q[index] - 1;
delay_before_read_counter_d[index] = (delay_before_read_counter_q[index] == 0)? 0:delay_before_read_counter_q[index] - 1;
end
for(index = 1; index < READ_ACK_PIPE_WIDTH; index = index + 1) begin
// shift is rightward where LSB gets MSB ([MSB] -> [] -> [] -> .... -> [] -[LSB])
shift_reg_read_pipe_d[index-1] = shift_reg_read_pipe_q[index];
end
shift_reg_read_pipe_d[READ_ACK_PIPE_WIDTH-1] = 0; //MSB just receives zero when shifted rightward
//USE _d in ALL
//if there is a pending request, issue the appropriate commands
if(stage2_pending) begin
stage2_stall = 1; //initially high when stage 2 is pending
stage2_update = 0;
//right row is already active so go straight to read/write
if(bank_status_q[stage2_bank] && bank_active_row_q[stage2_bank] == stage2_row) begin //read/write operation
//write request
if(stage2_we && delay_before_write_counter_q[stage2_bank] == 0) begin
stage2_stall = 0;
stage2_update = 1;
cmd_odt = 1'b1;
shift_reg_read_pipe_d[READ_ACK_PIPE_WIDTH-1] = {stage2_aux, 1'b1}; // ack is sent to shift_reg which will be shifted until the wb ack output
//write acknowledge will use the same logic pipeline as the read acknowledge.
//This would mean write ack latency will be the same for
//read ack latency. If it takes 8 clocks for read ack, write
//ack latency will be the same. This simplifies the logic
//for write ack as there will be no need to analyze the
//contents of the shift_reg_read_pipe just to determine
//where best to place the write ack on the pipeline (since
//the order of ack must be maintained). But this would mean
//the latency for write is fixed regardless if there is an
//outstanding read ack or none on the pipeline. But this is
// acceptable in my opinion since this is a pipelined wishbone
// where the transaction can continue regardless when ack returns
//set-up delay before precharge, read, and write
if(delay_before_precharge_counter_q[stage2_bank] <= WRITE_TO_PRECHARGE_DELAY) begin
//it is possible that the delay_before_precharge is
//set to tRAS (activate to precharge delay). And if we
//overwrite delay_before_precharge, we might overwrite
//the delay to a lower value which will violate the
//tRAS requirement. Thus, we must first check if the
//delay_before_precharge is set to a value not more
//than the WRITE_TO_PRECHARGE_DELAY
delay_before_precharge_counter_d[stage2_bank] = WRITE_TO_PRECHARGE_DELAY;
end
for(index=0; index < (1<<BA_BITS); index=index+1) begin //the write to read delay applies to all banks (odt must be turned off properly before reading)
delay_before_read_counter_d[index] = WRITE_TO_READ_DELAY + 1; //NOTE TO SELF: why plus 1?
end
delay_before_read_counter_d[stage2_bank] = WRITE_TO_READ_DELAY + 1;
delay_before_write_counter_d[stage2_bank] = WRITE_TO_WRITE_DELAY;
//issue read command
if(COL_BITS <= 10) begin
cmd_d[WRITE_SLOT] = {1'b0, CMD_WR[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank,{{ROW_BITS-32'd11}{1'b0}} , 1'b0 , stage2_col[9:0]};
end
else begin // COL_BITS > 10 has different format from <= 10
cmd_d[WRITE_SLOT] = {1'b0, CMD_WR[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank,{{ROW_BITS-32'd12}{1'b0}} , stage2_col[(COL_BITS <= 10) ? 0 : 10] , 1'b0 , stage2_col[9:0]};
end
//turn on odt at same time as write cmd
cmd_d[0][CMD_ODT] = cmd_odt;
cmd_d[1][CMD_ODT] = cmd_odt;
cmd_d[2][CMD_ODT] = cmd_odt;
cmd_d[3][CMD_ODT] = cmd_odt;
write_dqs_d=1;
write_dq_d=1;
end
//read request
else if(!stage2_we && delay_before_read_counter_q[stage2_bank]==0) begin
stage2_stall = 0;
stage2_update = 1;
cmd_odt = 1'b0;
//set-up delay before precharge, read, and write
if(delay_before_precharge_counter_q[stage2_bank] <= READ_TO_PRECHARGE_DELAY) begin
delay_before_precharge_counter_d[stage2_bank] = READ_TO_PRECHARGE_DELAY;
end
delay_before_read_counter_d[stage2_bank] = READ_TO_READ_DELAY;
delay_before_write_counter_d[stage2_bank] = READ_TO_WRITE_DELAY + 1; //temporary solution since its possible odt to go high already while reading previously
for(index=0; index < (1<<BA_BITS); index=index+1) begin //the read to write delay applies to all banks (odt must be turned on properly before writing and this delay is for ODT to settle)
delay_before_write_counter_d[index] = READ_TO_WRITE_DELAY + 1; // NOTE TO SELF: why plus 1?
end
shift_reg_read_pipe_d[READ_ACK_PIPE_WIDTH-1] = {stage2_aux, 1'b1}; // ack is sent to shift_reg which will be shifted until the wb ack output
//issue read command
if(COL_BITS <= 10) begin
cmd_d[READ_SLOT] = {1'b0, CMD_RD[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank, {{ROW_BITS-32'd11}{1'b0}} , 1'b0 , stage2_col[9:0]};
end
else begin // COL_BITS > 10 has different format from <= 10
cmd_d[READ_SLOT] = {1'b0, CMD_RD[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank, {{ROW_BITS-32'd12}{1'b0}} , stage2_col[(COL_BITS <= 10) ? 0 : 10] , 1'b0 , stage2_col[9:0]};
end
//turn off odt at same time as read cmd
cmd_d[0][CMD_ODT] = cmd_odt;
cmd_d[1][CMD_ODT] = cmd_odt;
cmd_d[2][CMD_ODT] = cmd_odt;
cmd_d[3][CMD_ODT] = cmd_odt;
end
end
//bank is idle so activate it
else if(!bank_status_q[stage2_bank] && delay_before_activate_counter_q[stage2_bank] == 0) begin
activate_slot_busy = 1'b1;
delay_before_precharge_counter_d[stage2_bank] = ACTIVATE_TO_PRECHARGE_DELAY;
//set-up delay before read and write
if(delay_before_read_counter_q[stage2_bank] <= ACTIVATE_TO_READ_DELAY) begin // if current delay is > ACTIVATE_TO_READ_DELAY, then updating it to the lower delay will cause the previous delay to be violated
delay_before_read_counter_d[stage2_bank] = ACTIVATE_TO_READ_DELAY;
end
if(delay_before_write_counter_q[stage2_bank] <= ACTIVATE_TO_WRITE_DELAY) begin // if current delay is > ACTIVATE_TO_WRITE_DELAY, then updating it to the lower delay will cause the previous delay to be violated
delay_before_write_counter_d[stage2_bank] = ACTIVATE_TO_WRITE_DELAY;
end
//issue activate command
cmd_d[ACTIVATE_SLOT] = {1'b0, CMD_ACT[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank , stage2_row};
//update bank status and active row
bank_status_d[stage2_bank] = 1'b1;
bank_active_row_d[stage2_bank] = stage2_row;
end
//bank is not idle but wrong row is activated so do precharge
else if(bank_status_q[stage2_bank] && bank_active_row_q[stage2_bank] != stage2_row && delay_before_precharge_counter_q[stage2_bank] ==0) begin
precharge_slot_busy = 1'b1;
//set-up delay before activate
delay_before_activate_counter_d[stage2_bank] = PRECHARGE_TO_ACTIVATE_DELAY;
//issue precharge command
cmd_d[PRECHARGE_SLOT] = {1'b0, CMD_PRE[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage2_bank, { {{ROW_BITS-32'd11}{1'b0}} , 1'b0 , stage2_row[9:0] } };
//update bank status and active row
bank_status_d[stage2_bank] = 1'b0;
end
end //end of stage 2 pending
//pending request on stage 1
if(stage1_pending && !((stage1_next_bank == stage2_bank) && stage2_pending)) begin
//stage 1 will mainly be for anticipation (if next requests need to jump to new bank then
//anticipate the precharging and activate of that next bank, BUT it can also handle
//precharge and activate of CURRENT wishbone request.
//Anticipate will depend if the request is on the end of the row
// and must start the anticipation. For example if we have 10 rows in a bank:
//[R][R][R][R][R][R][R][A][A][A] -> [next bank]
//
//R = Request, A = Anticipate
//Unless we are near the third to the last column, stage 1 will
//issue Activate and Precharge on the CURRENT bank. Else, stage
//1 will issue Activate and Precharge for the NEXT bank
// Thus stage 1 anticipate makes sure smooth burst operation that jumps banks
if(bank_status_q[stage1_next_bank] && bank_active_row_q[stage1_next_bank] != stage1_next_row && delay_before_precharge_counter_q[stage1_next_bank] ==0 && !precharge_slot_busy) begin
//set-up delay before read and write
delay_before_activate_counter_d[stage1_next_bank] = PRECHARGE_TO_ACTIVATE_DELAY;
cmd_d[PRECHARGE_SLOT] = {1'b0, CMD_PRE[2:0], cmd_odt, cmd_ck_en, cmd_reset_n, stage1_next_bank, { {{ROW_BITS-32'd11}{1'b0}} , 1'b0 , stage1_next_row[9:0] } };
bank_status_d[stage1_next_bank] = 1'b0;
end //end of anticipate precharge
//anticipated bank is idle so do activate
else if(!bank_status_q[stage1_next_bank] && delay_before_activate_counter_q[stage1_next_bank] == 0 && !activate_slot_busy) begin
delay_before_precharge_counter_d[stage1_next_bank] = ACTIVATE_TO_PRECHARGE_DELAY;
//set-up delay before read and write
if(delay_before_read_counter_d[stage1_next_bank] <= ACTIVATE_TO_READ_DELAY) begin // if current delay is > ACTIVATE_TO_READ_DELAY, then updating it to the lower delay will cause the previous delay to be violated
delay_before_read_counter_d[stage1_next_bank] = ACTIVATE_TO_READ_DELAY;
end
if(delay_before_write_counter_d[stage1_next_bank] <= ACTIVATE_TO_WRITE_DELAY) begin // if current delay is > ACTIVATE_TO_WRITE_DELAY, then updating it to the lower delay will cause the previous delay to be violated
delay_before_write_counter_d[stage1_next_bank] = ACTIVATE_TO_WRITE_DELAY;
end
cmd_d[ACTIVATE_SLOT] = {1'b0, CMD_ACT[2:0] , cmd_odt, cmd_ck_en, cmd_reset_n, stage1_next_bank , stage1_next_row};
bank_status_d[stage1_next_bank] = 1'b1;
bank_active_row_d[stage1_next_bank] = stage1_next_row;
end //end of anticipate activate
end //end of stage1 anticipate
// control stage 1 stall
if(stage1_pending) begin //raise stall only if stage2 will still be busy next clock
// Stage1 bank and row will determine if transaction will be
// stalled (bank is idle OR wrong row is active).
if(!bank_status_d[stage1_bank] || (bank_status_d[stage1_bank] && bank_active_row_d[stage1_bank] != stage1_row)) begin
stage1_stall = 1;
end
else if(!stage1_we && delay_before_read_counter_d[stage1_bank] != 0) begin // if read request but delay before read is not yet met then stall
stage1_stall = 1;
end
else if(stage1_we && delay_before_write_counter_d[stage1_bank] != 0) begin // if write request but delay before write is not yet met then stall
stage1_stall = 1;
end
//different request type will need a delay of more than 1 clk cycle so stall the pipeline
//if(stage1_we != stage2_we) begin
// stage1_stall = 1;
//end
end
//control stage 2 stall
if(stage2_pending) begin
//control stage2 stall in advance
if(bank_status_d[stage2_bank] && bank_active_row_d[stage2_bank] == stage2_row) begin //read/write operation
//write request
if(stage2_we && delay_before_write_counter_d[stage2_bank] == 0) begin // if write request and delay before write is already met then deassert stall
stage2_stall = 0; //to low stall next stage, but not yet at this stage
end
//read request
else if(!stage2_we && delay_before_read_counter_d[stage2_bank]==0) begin // if read request and delay before read is already met then deassert stall
stage2_stall = 0;
end
end
end
// control logic for stall
// this small logic is already optimized via listing all possible combinations on excel sheet, investigating the patterns
// and passing the formal verification. I recommend to not touch this and just left this as is.
// This logic makes sure stall will never go high unless the pipeline is full
// What made this complicated is that fact you have to predict the stall for next clock cycle in such
// a way that it will only stall next clock cycle if the pipeline will be full on the next clock cycle.
// Excel sheet: https://1drv.ms/x/s!AhWdq9CipeVagSqQXPwRmXhDgttL?e=vVYIxE&nav=MTVfezAwMDAwMDAwLTAwMDEtMDAwMC0wMDAwLTAwMDAwMDAwMDAwMH0
if(o_wb_stall_q) o_wb_stall_d = stage2_stall;
else if( (!i_wb_stb && state_calibrate == DONE_CALIBRATE) || (!calib_stb && state_calibrate != DONE_CALIBRATE) ) o_wb_stall_d = 0;
else if(!stage1_pending) o_wb_stall_d = stage2_stall;
else o_wb_stall_d = stage1_stall;
if(!i_wb_cyc && state_calibrate == DONE_CALIBRATE) o_wb_stall_d = 0;
end //end of always block
assign o_phy_cmd = {cmd_d[3], cmd_d[2], cmd_d[1], cmd_d[0]};
/*********************************************************************************************************************************************/
/******************************************************* Align Read Data from ISERDES *******************************************************/
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
index_read_pipe <= 0;
index_wb_data <= 0;
write_dqs_val <= 0;
write_dqs_q <= 0;
write_dqs <= 0;
write_dq_q <= 0;
write_dq <= 0;
for(index = 0; index < 2; index = index + 1) begin
delay_read_pipe[index] <= 0;
end
for(index = 0; index < 2; index = index + 1) begin
o_wb_data_q[index] <= 0;
end
for(index = 0; index < READ_ACK_PIPE_WIDTH; index = index + 1) begin
shift_reg_read_pipe_q[index] <= 0;
end
for(index = 0; index < MAX_ADDED_READ_ACK_DELAY ; index = index + 1) begin
o_wb_ack_read_q[index] <= 0;
end
end
else begin
if(ODELAY_SUPPORTED) begin
write_dqs_val[0] <= write_dqs_d || write_dqs_q[0];
end
else begin
write_dqs_val[0] <= write_dqs_d || write_dqs_q[0] || write_dqs_q[1];
end
write_dqs_q[0] <= write_dqs_d;
write_dqs_q[1] <= write_dqs_q[0];
write_dqs[0] <= write_dqs_d || write_dqs_q[0] || write_dqs_q[1]; //high for 3 clk cycles
write_dq_q[0] <= write_dq_d;
write_dq_q[1] <= write_dq_q[0];
write_dq[0] <= write_dq_d || write_dq_q[0] || write_dq_q[1]; //high for 3 clk cycles
for(index = 0; index < STAGE2_DATA_DEPTH; index = index+1) begin //increase by 1 to accomodate postamble
write_dqs[index+1] <= write_dqs[index];
write_dqs_val[index+1] <= write_dqs_val[index];
end
for(index = 0; index < STAGE2_DATA_DEPTH+1; index = index+1) begin //increase by 1 to accomodate postamble
write_dq[index+1] <= write_dq[index];
end
for(index = 0; index < READ_ACK_PIPE_WIDTH; index = index + 1) begin
// shifted rightward where LSB gets MSB ([MSB] -> [] -> [] -> .... -> [] -[LSB])
shift_reg_read_pipe_q[index] <= shift_reg_read_pipe_d[index];
end
for(index = 0; index < 2; index = index + 1) begin
// there are 2 read_pipes (each with 16 space for shifting), and each read pipes shift rightward
// so the bit 1 will be shifted to the right until it reach LSB which means data is already on ISERDES output of PHY
delay_read_pipe[index] <= (delay_read_pipe[index] >> 1);
end
if(shift_reg_read_pipe_q[1][0]) begin
//delay from shift_reg_read_pipe_q is about to be over (ack, which is the last bit, will be at LSB on next clk cycle)
//and data is now starting to be released from ISERDES from phy BUT NOT YET ALIGNED
index_read_pipe <= !index_read_pipe; //control which delay_read_pipe would get updated (we have 2 read_pipes to store read data,use the read_pipe alternatingly)
delay_read_pipe[index_read_pipe][added_read_pipe_max] <= 1'b1; //update delay_read_pipe
// NOTE: added_read_pipe_max can either be 0 or 1 (NOTE TO SELF: optimize by lowering the bit size of delay_read_pipe)
// delay_read_pipe will get the ack bit from shift_reg_read_pipe_q[1] at the bit equal to
// added_read_pipe_max (0th or 1st bit). added_read_pipe_max is the max number of added controller clk cycles among all lanes
// So basically, the delay_read_pipe is the delay to make sure the "added_read_pipe_max" controller clk cycles
// will be met.
// Example:
// So for request #1 (e.g. write request, added_read_pipe_max=1), wait until the shift_reg_read_pipe_q[1] goes
// high (READ_ACK_PIPE_WIDTH of delay is met which means the data from ISERDES PHY is now available). The
// delay_read_pipe[0][1] will then be high. This high bit on read_pipe #0 will get shifted to LSB. [1] -> [] -> [LSB]
// Meanwhile when request #2 comes (e.g. read request, added_read_pipe_max=1), again wait until the shift_reg_read_pipe_q[1] goes
// high. The delay_read_pipe[1][1] will then be high. This high bit on read_pipe #1 will get shifted to LSB. [1] -> [] -> [LSB]
end
for(index = 0; index < LANES; index = index + 1) begin
/* verilator lint_off WIDTH */
// read_pipe #0
// NOTE: added_read_pipe_max and added_read_pipe can either be just 0 or 1 (NOTE TO SELF: optimize by lowering the bit size of this)
// If the added_read_pipe (added number of controller clk cycles of delay to a lane due to pcb trace) is equal to the
// max delay (added_read_pipe_max, e.g. 0-0 or 1-1) for this lane, THEN we need to wait until the bit 1 reaches the LSB[0] of delay_read_pipe
// before retrieving the value from PHY. But if not the same (added_read_pipe is 0 while added_read_pipe_max is 1), then wait until
// the bit 1 reaches the one before LSB [1] before retrieving the value from PHY, so this means this lane with 0 delay will FIRST BE RETRIEVED
// while the lane with added_read_pipe_max of delay (delay of 1) will be retrieved SECOND
if(delay_read_pipe[0][added_read_pipe_max != added_read_pipe[index]]) begin
/* verilator lint_on WIDTH */
o_wb_data_q[0][((DQ_BITS*LANES)*0 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*0 + 8*index) +: 8]; //update lane for burst 0
o_wb_data_q[0][((DQ_BITS*LANES)*1 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*1 + 8*index) +: 8]; //update lane for burst 1
o_wb_data_q[0][((DQ_BITS*LANES)*2 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*2 + 8*index) +: 8]; //update lane for burst 2
o_wb_data_q[0][((DQ_BITS*LANES)*3 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*3 + 8*index) +: 8]; //update lane for burst 3
o_wb_data_q[0][((DQ_BITS*LANES)*4 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*4 + 8*index) +: 8]; //update lane for burst 4
o_wb_data_q[0][((DQ_BITS*LANES)*5 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*5 + 8*index) +: 8]; //update lane for burst 5
o_wb_data_q[0][((DQ_BITS*LANES)*6 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*6 + 8*index) +: 8]; //update lane for burst 6
o_wb_data_q[0][((DQ_BITS*LANES)*7 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*7 + 8*index) +: 8]; //update lane for burst 7
end
/* verilator lint_off WIDTH */
// read_pipe #1
// NOTE: added_read_pipe_max and added_read_pipe can either be just 0 or 1 (NOTE TO SELF: optimize by lowering the bit size of this)
// If the added_read_pipe (added number of controller clk cycles of delay to a lane due to pcb trace) is equal to the
// max delay (added_read_pipe_max, e.g. 0-0 or 1-1) for this lane, THEN we need to wait until the bit 1 reaches the LSB[0] of delay_read_pipe
// before retrieving the value from PHY. But if not the same (added_read_pipe is 0 while added_read_pipe_max is 1), then wait until
// the bit 1 reaches the one before LSB [1] (which goes high already since bit 1 of delay_read_pipe is the first to go high once shift_reg_read_pipe_q
// bit 1 goes high) before retrieving the value from PHY. So this means this lane with 0 delay will FIRST BE RETRIEVED
// while the lane with added_read_pipe_max of delay (delay of 1) will be retrieved SECOND
if(delay_read_pipe[1][added_read_pipe_max != added_read_pipe[index]]) begin
/* verilator lint_on WIDTH */
o_wb_data_q[1][((DQ_BITS*LANES)*0 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*0 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*1 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*1 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*2 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*2 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*3 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*3 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*4 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*4 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*5 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*5 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*6 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*6 + 8*index) +: 8]; //update each lane of the burst
o_wb_data_q[1][((DQ_BITS*LANES)*7 + 8*index) +: 8] <= i_phy_iserdes_data[((DQ_BITS*LANES)*7 + 8*index) +: 8]; //update each lane of the burst
end
// why are we alternatingly use the read_pipes?
// time | 0 | 1 | 2 | 3 |
// index_read_pipe | 1 | 0 | 1 | 0 |
// delay_read_pipe[1] | [0][0] | <[1][0] | [0][1]> | [1][0] |
// delay_read_pipe[0] | [0][0] | [0][0] | <[1][0] | [0][1]> |
//
// At time 1, request #1 is accepted by pipe[1], then wait until time 2 to retrieve the lane with longest added_read_pipe
// (lane with added_read_pipe 0 is retrieved from ISERDES at time 1, lane with added_read_pipe 1 is retrieved from ISERDES at time 2)
// At time 2, request #2 is accepted by pipe[0] (since pipe[1] is still busy on request #1), then wait until time 3 to retrieve
// the lane with longest added_read_pipe
// Thus pipe 0 and 1 is alternating to make sure that even if 0 is busy, 1 will retrieve the data. And then when 1 is busy, 0 will retrieve the data
// NOTE TO SELF: longest delay for a lane relative to others is 1 controller clk cycle, if more than 1 then it will not be retrievd
// and aligned properly. Thus try to optimize this logic since delay is at max 1 controller clk only.
end
// o_wb_ack_read_q[0][0] is also the wishbone ack (aligned with ack is the wishbone data) thus
// after sending the wishbone data on a particular index, invert it for the next ack
if(o_wb_ack_read_q[0][0]) begin
index_wb_data <= !index_wb_data; //alternatingly uses the o_wb_data_q (either 0 or 1)
end
for(index = 1; index < MAX_ADDED_READ_ACK_DELAY; index = index + 1) begin
o_wb_ack_read_q[index-1] <= o_wb_ack_read_q[index]; // shift rightward [ack] -> [] -> [LSB]
end
o_wb_ack_read_q[MAX_ADDED_READ_ACK_DELAY-1] <= 0; // MSB always gets zero and is shifted rightwards
o_wb_ack_read_q[added_read_pipe_max] <= shift_reg_read_pipe_q[0];
// o_wb_ack_read_q[0] is the wishbone ack
// so once data is available from ISERDES (shift_reg_read_pipe_q[0] high) then need to wait added_read_pipe_max
// before the data is properly stored to o_wb_data_q and can be sent outside as wishbone data
// BASICALLY:
// shift_reg_read_pipe_q is the delay from when the read command is issued from controller until the
// data is received by the PHY ISERDES (total delay of READ_ACK_PIPE_WIDTH). The shift_reg_read_pipe_q[1]
// is then connected to delay_read_pipe[added_read_pipe_max (0 or 1)] which is the delay to align the lanes.
// The shift_reg_read_pipe_q[0] is then connected to o_wb_ack_read_q[added_read_pipe_max (0 or 1)] which
// is the delay until the wishbone data and ack will be sent outside
// NOTE TO SELF: Optimize by removing o_wb_ack_read_q and just connect the woshbone ack and data to delay_read_pipe[0].
// Visualization:
// shift_reg_read_pipe_q [ ] -> [1] -> [ ] [ ] -> [ ] -> [1] [ ] -> [ ] -> [ ] [ ] -> [ ] -> [ ]
// delay_read_pipe [ ] -> [ ] -> [ ] ---> [ ] -> [1] -> [ ] ---> [ ] -> [ ] -> [1] ---> [ ] -> [ ] -> [ ]
// o_wb_ack_read_q [ ] -> [ ] -> [ ] [ ] -> [ ] -> [ ] [ ] -> [1] -> [ ] [ ] -> [ ] -> [1]
// request is now on [1] request passed request passed o_wb_ack_read_q[0]
// of shift_reg_read_pipe_q to delay_read_pipe to o_wb_ack_read_q high thus ready for wishbone ack
// abort any outgoing ack when cyc is low
if(!i_wb_cyc && state_calibrate == DONE_CALIBRATE) begin
for(index = 0; index < MAX_ADDED_READ_ACK_DELAY; index = index + 1) begin
o_wb_ack_read_q[index] <= 0;
end
for(index = 0; index < READ_ACK_PIPE_WIDTH; index = index + 1) begin
shift_reg_read_pipe_q[index] <= 0;
end
end
end
end
assign o_wb_ack = o_wb_ack_read_q[0][0] && state_calibrate == DONE_CALIBRATE;
//o_wb_ack_read_q[0][0] is needed internally to ack during write calibration but it must not go outside (since it is not an actual user wb request unless we are in DONE_CALIBRATE)
assign o_aux = o_wb_ack_read_q[0][AUX_WIDTH:1];
assign o_wb_data = o_wb_data_q[index_wb_data];
assign o_phy_dqs_tri_control = !write_dqs[STAGE2_DATA_DEPTH];
assign o_phy_dq_tri_control = !write_dq[STAGE2_DATA_DEPTH];
generate
if(STAGE2_DATA_DEPTH >= 2) begin: TOGGLE_DQS
assign o_phy_toggle_dqs = write_dqs_val[STAGE2_DATA_DEPTH-2];
end
else begin: TOGGLE_DQS_DEPTH_LESS_2
assign o_phy_toggle_dqs = write_dqs_d || write_dqs_q[0];
end
endgenerate
/*********************************************************************************************************************************************/
/******************************************************* Read/Write Calibration Sequence *******************************************************/
reg[$clog2(wb_sel_bits)-1:0] write_by_byte_counter = 0;
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
state_calibrate <= IDLE;
train_delay <= 0;
dqs_store <= 0;
dqs_count_repeat <= 0;
dqs_start_index <= 0;
dqs_target_index <= 0;
dqs_target_index_orig <= 0;
o_phy_bitslip <= 0;
o_phy_odelay_data_ld <= 0;
o_phy_odelay_dqs_ld <= 0;
o_phy_idelay_data_ld <= 0;
o_phy_idelay_dqs_ld <= 0;
lane_times_8 <= 0;
idelay_data_cntvaluein_prev <= 0;
initial_dqs <= 1;
lane <= 0;
dqs_bitslip_arrangement <= 0;
write_calib_dqs <= 0;
write_calib_dq <= 0;
write_calib_odt <= 0;
prev_write_level_feedback <= 1;
calib_stb <= 0;//actual request flag
calib_sel <= 0;
calib_aux <= 0; //AUX ID
calib_we <= 0; //write-enable
calib_addr <= 0;
calib_data <= 0;
pause_counter <= 0;
read_data_store <= 0;
write_pattern <= 0;
added_read_pipe_max <= 0;
dqs_start_index_stored <= 0;
dqs_start_index_repeat <= 0;
delay_before_write_level_feedback <= 0;
delay_before_read_data <= 0;
read_lane_data <= 0;
o_phy_write_leveling_calib <= 0;
odelay_cntvalue_repeated <= 0;
write_level_fail <= 0;
read_test_address_counter <= 0;
write_test_address_counter <= 0;
reset_from_calibrate <= 0;
write_by_byte_counter <= 0;
already_finished_calibration <= 0;
for(index = 0; index < LANES; index = index + 1) begin
added_read_pipe[index] <= 0;
data_start_index[index] <= 0;
odelay_data_cntvaluein[index] <= DATA_INITIAL_ODELAY_TAP[4:0];
odelay_dqs_cntvaluein[index] <= DQS_INITIAL_ODELAY_TAP[4:0];
idelay_data_cntvaluein[index] <= DATA_INITIAL_IDELAY_TAP[4:0];
idelay_dqs_cntvaluein[index] <= DQS_INITIAL_IDELAY_TAP[4:0];
dq_target_index[index] <= 0;
end
end
else begin
write_calib_dq <= 0;
train_delay <= (train_delay==0)? 0:(train_delay - 1);
delay_before_read_data <= (delay_before_read_data == 0)? 0: delay_before_read_data - 1;
delay_before_write_level_feedback <= (delay_before_write_level_feedback == 0)? 0: delay_before_write_level_feedback - 1;
o_phy_bitslip <= 0;
o_phy_odelay_data_ld <= 0;
o_phy_odelay_dqs_ld <= 0;
o_phy_idelay_data_ld <= 0;
o_phy_idelay_dqs_ld <= 0;
/* verilator lint_off WIDTH */
lane_times_8 <= lane << 3;
/* verilator lint_on WIDTH */
idelay_data_cntvaluein_prev <= idelay_data_cntvaluein[lane];
reset_from_calibrate <= 0;
if(wb2_update) begin
odelay_data_cntvaluein[wb2_write_lane] <= wb2_phy_odelay_data_ld[wb2_write_lane]? wb2_phy_odelay_data_cntvaluein : odelay_data_cntvaluein[wb2_write_lane];
odelay_dqs_cntvaluein[wb2_write_lane] <= wb2_phy_odelay_dqs_ld[wb2_write_lane]? wb2_phy_odelay_dqs_cntvaluein : odelay_dqs_cntvaluein[wb2_write_lane];
idelay_data_cntvaluein[wb2_write_lane] <= wb2_phy_idelay_data_ld[wb2_write_lane]? wb2_phy_idelay_data_cntvaluein : idelay_data_cntvaluein[wb2_write_lane];
idelay_dqs_cntvaluein[wb2_write_lane] <= wb2_phy_idelay_dqs_ld[wb2_write_lane]? wb2_phy_idelay_dqs_cntvaluein : idelay_dqs_cntvaluein[wb2_write_lane];
o_phy_odelay_data_ld <= wb2_phy_odelay_data_ld;
o_phy_odelay_dqs_ld <= wb2_phy_odelay_dqs_ld;
o_phy_idelay_data_ld <= wb2_phy_idelay_data_ld;
o_phy_idelay_dqs_ld <= wb2_phy_idelay_dqs_ld;
lane <= wb2_write_lane;
end
else if(state_calibrate != DONE_CALIBRATE) begin
// increase cntvalue every load to prepare for possible next load
odelay_data_cntvaluein[lane] <= o_phy_odelay_data_ld[lane]? odelay_data_cntvaluein[lane] + 1: odelay_data_cntvaluein[lane];
odelay_dqs_cntvaluein[lane] <= o_phy_odelay_dqs_ld[lane]? odelay_dqs_cntvaluein[lane] + 1: odelay_dqs_cntvaluein[lane];
idelay_data_cntvaluein[lane] <= o_phy_idelay_data_ld[lane]? idelay_data_cntvaluein[lane] + 1: idelay_data_cntvaluein[lane];
idelay_dqs_cntvaluein[lane] <= o_phy_idelay_dqs_ld[lane]? idelay_dqs_cntvaluein[lane] + 1: idelay_dqs_cntvaluein[lane];
end
// high initial_dqs is the time when the IDELAY of dqs and dq is not yet calibrated
// dqs_target_index_value = dqs_start_index_stored[0]? dqs_start_index_stored + 2: dqs_start_index_stored + 1; // move to next odd (if 3 then 5, if 4 then 5)
// so dqs_target_index_value is basically the next odd number of dqs_start_index_stored (original starting bit when dqs starts).
// The next odd number ensure that the DQS edge is aligned to edge of ddr3_clk (and thus DQ data eye is aligned to edges of of ddr3_clk
// since dq is 90 degree relative to dqs
// Some images to show why next odd number is used: https://github.com/AngeloJacobo/UberDDR3/tree/b762c464f6526159c1d8c2e4ee039b4ae4e78dbd#per-lane-read-calibration
if(initial_dqs) begin
dqs_target_index <= dqs_target_index_value; // target index for DQS to make sure the DQS is edge-aligned with ddr3_clk
dq_target_index[lane] <= {1'b0, dqs_target_index_value}; // target index for DQ (just same as DQS)
dqs_target_index_orig <= dqs_target_index_value; // this will remain the same until we finish calibrating this whole lane
end
if(idelay_dqs_cntvaluein[lane] == 0) begin //the DQS got past cntvalue of 31 (and goes back to zero) THUS the target index should also go back (to previous odd)
dqs_target_index <= dqs_target_index_orig - 2;
end
if(idelay_data_cntvaluein[lane] == 0 && idelay_data_cntvaluein_prev == 31) begin //the DQ got past cntvalue of 31 (and goes back to zero) thus the target index should also go back (to previous odd)
dq_target_index[lane] <= dqs_target_index_orig - 2;
end
// FSM
case(state_calibrate)
IDLE: if(i_phy_idelayctrl_rdy && instruction_address == 13) begin //we are now inside instruction 15 with maximum delay
state_calibrate <= BITSLIP_DQS_TRAIN_1;
lane <= 0;
o_phy_odelay_data_ld <= {LANES{1'b1}};
o_phy_odelay_dqs_ld <= {LANES{1'b1}};
o_phy_idelay_data_ld <= {LANES{1'b1}};
o_phy_idelay_dqs_ld <= {LANES{1'b1}};
pause_counter <= 1; //pause instruction address @13 until read calibration finishes
write_calib_dqs <= 0;
write_calib_odt <= 0;
o_phy_write_leveling_calib <= 0;
end
else if(instruction_address == 13) begin
pause_counter <= 1; //pause instruction address @13 until read calibration finishes
end
BITSLIP_DQS_TRAIN_1: if(train_delay == 0) begin
/* Bitslip cannot be asserted for two consecutive CLKDIV cycles; Bitslip must be
deasserted for at least one CLKDIV cycle between two Bitslip assertions.The user
logic should wait for at least two CLKDIV cycles in SDR mode or three CLKDIV cycles
in DDR mode, before analyzing the received data pattern and potentially issuing
another Bitslip command. If the ISERDESE2 is reset, the Bitslip logic is also reset
and returns back to its initial state.
*/
// bitslip basically is changing the arrangement of bytes on IOSERDES
if(i_phy_iserdes_bitslip_reference[lane*serdes_ratio*2 +: 8] == 8'b0111_1000) begin //initial arrangement
state_calibrate <= MPR_READ;
initial_dqs <= 1;
dqs_start_index_repeat <= 0;
dqs_start_index_stored <= 0;
end
else begin
o_phy_bitslip[lane] <= 1;
train_delay <= 3;
end
end
MPR_READ: if(delay_before_read_data == 0) begin //align the incoming DQS during reads to the controller clock
//issue_read_command = 1;
/* verilator lint_off WIDTH */
delay_before_read_data <= READ_DELAY + 1 + 2 + 1 - 1; ///NOTE TO SELF: why these numbers? 1=issue command delay (OSERDES delay), 2 = ISERDES delay
/* verilator lint_on WIDTH */
state_calibrate <= COLLECT_DQS;
dqs_count_repeat <= 0;
end
COLLECT_DQS: if(delay_before_read_data == 0) begin // data from MPR read is now received by controller
// dqs from ISERDES is received and stored
// DQS received from ISERDES: { {LANE_1_burst_7, LANE_1_burst_6, ... , LANE_1_burst_0} , {LANE_0_burst_7, LANE_0_burst_6, ... , LANE_0_burst_0}}
// NOTE TO SELF: WHY DQS IS DIVIDED PER LANE BUT DQ IS PER BURST ????
// dqs_store stores the 8 DQS (8 bursts) for a given lane but since the DQS might be shifted at next ddr3 clk cycles (due to trace delays), we must store the
// 8 DQS multiple times (dictated by STORED_DQS_SIZE)
dqs_store <= {i_phy_iserdes_dqs[serdes_ratio*2*lane +: 8], dqs_store[(STORED_DQS_SIZE*8-1):8]};
dqs_count_repeat <= dqs_count_repeat + 1;
if(dqs_count_repeat == STORED_DQS_SIZE - 1) begin
state_calibrate <= ANALYZE_DQS;
// store the previous value of dqs_start_index, if the ANALYZE_DQS is repeated then the dqs_start_index
// should be the same as the previous value, else the previous (or current one) has a glitch causing
// a different dqs_start_index
dqs_start_index_stored <= dqs_start_index;
// start the index from zero since this will be incremented until we pinpoint the real
// starting bit of dqs_store (dictated by the pattern 10'b01_01_01_01_00)
dqs_start_index <= 0;
end
end
// find the bit where the DQS starts to be issued (by finding when the pattern 10'b01_01_01_01_00 starts)
ANALYZE_DQS: if(dqs_store[dqs_start_index +: 10] == 10'b01_01_01_01_00) begin
//increase dqs_start_index_repeat when index is the same as before
dqs_start_index_repeat <= (dqs_start_index == dqs_start_index_stored)? dqs_start_index_repeat + 1: 0;
//the same dqs_start_index_repeat appeared REPEAT_DQS_ANALYZE times in a row, thus we can trust the value we got is accurate and not affected by glitch
if(dqs_start_index_repeat == REPEAT_DQS_ANALYZE) begin
// since we already know the starting bit when the dqs (and dq since they are aligned) will come,
// we will now start calibrating the IDELAY for dqs and dq (via CALIBRATE_DQS).
// high initial_dqs is the time when the IDELAY of dqs and dq is not yet calibrated so we zero this starting now
initial_dqs <= 0;
dqs_start_index_repeat <= 0;
state_calibrate <= CALIBRATE_DQS;
end
else begin
state_calibrate <= MPR_READ;
end
end
else begin
if(dqs_start_index == (STORED_DQS_SIZE*8-1) ) begin //if we reached end then most likely we hit a glitch where 01_01_01_01_00 is muddied
o_phy_idelay_data_ld[lane] <= 1;
o_phy_idelay_dqs_ld[lane] <= 1;
state_calibrate <= MPR_READ;
delay_before_read_data <= 10; //wait for sometime to make sure idelay load settles
end
else begin
dqs_start_index <= dqs_start_index + 1;
end
end
// check if the index when the dqs starts is the same as the target index which is aligned to the ddr3_clk
// dqs_target_index is the next odd number to dqs_start_index BEFORE IDELAY CALIBRATION. We will increase the IDELAY
// until the dqs_start_index_stored (current value of dqs_start_index) matches the target index which is aligned to ddr3_clk
CALIBRATE_DQS: if(dqs_start_index_stored == dqs_target_index) begin
// dq_target_index still stores the original dqs_target_index_value. The bit size of dq_target_index is just enough
// to count the bits in dqs_store (the received 8 DQS stored STORED_DQS_SIZE times)
added_read_pipe[lane] <= { {( 4 - ($clog2(STORED_DQS_SIZE*8) - (3+1)) ){1'b0}} , dq_target_index[lane][$clog2(STORED_DQS_SIZE*8)-1:(3+1)] }
+ { 3'b0 , (dq_target_index[lane][3:0] >= (5+8)) };
// if target_index is > 13, then a 1 CONTROLLLER_CLK cycle delay (4 ddr3_clk cycles) is added on that particular lane (due to trace delay)
// added_read_pipe[lane] <= dq_target_index[lane][$clog2(STORED_DQS_SIZE*8)-1 : (4)] + ( dq_target_index[lane][3:0] >= 13 ) ;
dqs_bitslip_arrangement <= 16'b0011_1100_0011_1100 >> dq_target_index[lane][2:0];
// the dqs is delayed (to move starting bit to next odd number) so this means the original
// expected bitslip arrangement of 8'b0111_1000 will not be followed anymore, so here we form the bitslip
// arrangement pattern so incoming dqs (and thus DQ) is arranged in the proper way (first bute firs, last byte last)
state_calibrate <= BITSLIP_DQS_TRAIN_2;
end
else begin
// if we have not yet reached the target index then increment IDELAY
// we will keep incrementing the IDELAY until the next odd index is reached (which is
// the time we are sure the DQS is edge aligned with ddr3_clk and thus ddr3_clk posedge
// is hitting the center of DQ eye
// To show why next odd number is needed: https://github.com/AngeloJacobo/UberDDR3/tree/b762c464f6526159c1d8c2e4ee039b4ae4e78dbd#per-lane-read-calibration
o_phy_idelay_data_ld[lane] <= 1;
o_phy_idelay_dqs_ld[lane] <= 1;
state_calibrate <= MPR_READ;
delay_before_read_data <= 10; //wait for sometime to make sure idelay load settles
end
//the dqs is delayed (to move starting bit to next odd number) so this means the original
// expected bitslip arrangement of 8'b0111_1000 will not be followed anymore, so here the bitslip
// is re-arranged
BITSLIP_DQS_TRAIN_2: if(train_delay == 0) begin //train again the ISERDES to capture the DQ correctly
if(i_phy_iserdes_bitslip_reference[lane*serdes_ratio*2 +: 8] == dqs_bitslip_arrangement[7:0]) begin
/* verilator lint_off WIDTH */
// this is the end of training and calibration for a single lane, so proceed to next lane
if(lane == LANES - 1) begin
/* verilator lint_on WIDTH */
pause_counter <= 0; //read calibration now complete so continue the reset instruction sequence
lane <= 0;
odelay_cntvalue_repeated <= 0;
prev_write_level_feedback <= 1'b1;
sample_clk_repeat <= 0;
stored_write_level_feedback <= 0;
o_phy_write_leveling_calib <= 1;
state_calibrate <= START_WRITE_LEVEL;
end
else begin
lane <= lane + 1;
state_calibrate <= BITSLIP_DQS_TRAIN_1;// current lane is done so go back to BITSLIP_DQS_TRAIN_1 to train next lane
end
// stores the highest value of added_read_pipe among the lanes since all lanes (except the lane with highest
// added_read_pipe) will be delayed to align with the lane with highest added_read_pipe. This alignment
// is required to make sure the received DQ will be aligned and can form the 512 bit data (for 8 lanes) arranged properly.
added_read_pipe_max <= added_read_pipe_max > added_read_pipe[lane]? added_read_pipe_max:added_read_pipe[lane];
end
else begin
o_phy_bitslip[lane] <= 1;
train_delay <= 3;
end
end
// CONTINUE COMMENT HERE (once blog is done)
START_WRITE_LEVEL: if(!ODELAY_SUPPORTED) begin //skip write levelling if ODELAY is not supported
pause_counter <= 0;
lane <= 0;
state_calibrate <= ISSUE_WRITE_1;
write_calib_odt <= 0;
o_phy_write_leveling_calib <= 0;
end
else if(instruction_address == 17) begin
write_calib_dqs <= 1'b1;
write_calib_odt <= 1'b1;
delay_before_write_level_feedback <= DELAY_BEFORE_WRITE_LEVEL_FEEDBACK[$clog2(DELAY_BEFORE_WRITE_LEVEL_FEEDBACK):0];
state_calibrate <= WAIT_FOR_FEEDBACK;
pause_counter <= 1; // pause instruction address @17 until write calibration finishes
end
WAIT_FOR_FEEDBACK: if(delay_before_write_level_feedback == 0) begin
/* verilator lint_off WIDTH */ //_verilator warning: Bit extraction of var[511:0] requires 9 bit index, not 3 bits (but [lane<<3] is much simpler and cleaner)
sample_clk_repeat <= (i_phy_iserdes_data[lane_times_8] == stored_write_level_feedback)? sample_clk_repeat + 1 : 0; //sample_clk_repeat should get the same response
stored_write_level_feedback <= i_phy_iserdes_data[lane_times_8];
write_calib_dqs <= 0;
if(sample_clk_repeat == REPEAT_CLK_SAMPLING) begin
sample_clk_repeat <= 0;
prev_write_level_feedback <= stored_write_level_feedback;
if(({prev_write_level_feedback, stored_write_level_feedback} == 2'b01) || write_level_fail[lane]) begin
/* verilator lint_on WIDTH */
/* verilator lint_off WIDTH */
if(lane == LANES - 1) begin
/* verilator lint_on WIDTH */
write_calib_odt <= 0;
pause_counter <= 0; //write calibration now complete so continue the reset instruction sequence
lane <= 0;
o_phy_write_leveling_calib <= 0;
state_calibrate <= ISSUE_WRITE_1;
end
else begin
lane <= lane + 1;
odelay_cntvalue_repeated <= 0;
prev_write_level_feedback <= 1'b1;
sample_clk_repeat <= 0;
state_calibrate <= START_WRITE_LEVEL;
end
end
else begin
o_phy_odelay_data_ld[lane] <= 1;
o_phy_odelay_dqs_ld[lane] <= 1;
write_level_fail[lane] <= (odelay_cntvalue_repeated && odelay_data_cntvaluein[lane] == 2);
state_calibrate <= START_WRITE_LEVEL;
end
end
end
ISSUE_WRITE_1: if(instruction_address == 22 && !o_wb_stall_calib) begin
calib_stb <= 1;//actual request flag
calib_aux <= 0; //AUX ID to determine later if ACK is for read or write
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= 1; //write-enable
calib_addr <= 0;
// burst_7 burst_6 burst_5 burst_4 burst_3 burst_2 burst_1 burst_0
calib_data <= { {LANES{8'h91}}, {LANES{8'h77}}, {LANES{8'h29}}, {LANES{8'h8c}}, {LANES{8'hd0}}, {LANES{8'had}}, {LANES{8'h51}}, {LANES{8'hc1}} };
// write to address 0 is a burst of 8 writes, where all lanes has same data written: 64'h9177298cd0ad51c1
// Example for LANES of 2, DQ of 8: the 128 bits (8 bursts * 2 lanes/burst * 8bits/lane) are 8 bursts with 8 bytes each:
// { burst_7, burst_6, burst_5, burst_4, burst_3, burst_2, burst_1, burst_0 } OR:
// { { {burst7_lane1} , {burst7_lane0} } , { {burst6_lane1} , {burst6_lane0} } , { {burst5_lane1} , {burst5_lane0} }
// , { {burst4_lane1} , {burst4_lane0} } , { {burst3_lane1} , {burst3_lane0} } , { {burst2_lane1} , {burst2_lane0} }
// , { {burst1_lane1} , {burst1_lane0} } , { {burst0_lane1} , {burst0_lane0} } }
state_calibrate <= ISSUE_WRITE_2;
end
ISSUE_WRITE_2: begin
calib_stb <= 1;//actual request flag
calib_aux <= 0; //AUX ID to determine later if ACK is for read or write
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= 1; //write-enable
calib_addr <= 1;
// burst_7 burst_6 burst_5 burst_4 burst_3 burst_2 burst_1 burst_0
calib_data <= { {LANES{8'h80}}, {LANES{8'hdb}}, {LANES{8'hcf}}, {LANES{8'hd2}}, {LANES{8'h75}}, {LANES{8'hf1}}, {LANES{8'h2c}}, {LANES{8'h3d}} };
// write to address 1 is also a burst of 8 writes, where all lanes has same data written: 128'h80dbcfd275f12c3d
state_calibrate <= ISSUE_READ;
end
// NOTE: WHY THERE ARE TWO ISSUE_WRITE
// address 0 and 1 is written with a deterministic data, if the DQ trace has long delay (relative to command line) then the data will be delayed
// compared to the write command. Thus the data aligned to the write command for address 0 MIGHT START AT MIDDLE OF EXPECTED OUTPUT
// DATA (64'h9177298cd0ad51c1) e.g. the data written might be 64'h[2c3d][9177298cd0ad] where the data written starts
// at burst 2 (burst 0 and burst 1 are cut-off since each burst uses 1 ddr3_clk cycle)
// Note here that if DQ and DQS sa same delay, then we know the DQS will always be aligned with DQ data
ISSUE_READ: begin
calib_stb <= 1;//actual request flag
calib_aux <= 1; //AUX ID to determine later if ACK is for read or write
calib_we <= 0; //write-enable
calib_addr <= 0;
state_calibrate <= READ_DATA;
end
READ_DATA: if(o_wb_ack_read_q[0] == {{(AUX_WIDTH-2){1'b0}}, 2'd1, 1'b1}) begin //wait for the read ack (which has AUX ID of 1}
read_data_store <= o_wb_data; // read data on address 0
calib_stb <= 0;
state_calibrate <= ANALYZE_DATA;
data_start_index[lane] <= 0;
// Possible Patterns (strong autocorrel stat)
//0x80dbcfd275f12c3d
//0x9177298cd0ad51c1
//0x01b79fa4ebe2587b
//0x22ee5319a15aa382
write_pattern <= 128'h80dbcfd275f12c3d_9177298cd0ad51c1;
end
else if(!o_wb_stall_calib) begin
calib_stb <= 0;
end
// extract burst_0-to-burst_7 data for a specified lane then determine which byte in write_pattern does it starts
// NOTE TO SELF: all "8" here assume DQ_BITS are 8? parameterize this properly
// data_start_index for a specified lane determine how many bits are off the data from the write command
// so for every 1 ddr3 clk cycle delay of DQ from write command, each lane will be 1 burst off:
// e.g. LANE={burst7, burst6, burst5, burst4, burst3, burst2, burst1, burst0} then with 1 ddr3 cycle delay between DQ and command
// burst0 will not be written but only starting on burst1
ANALYZE_DATA: if(write_pattern[data_start_index[lane] +: 64] == {read_data_store[((DQ_BITS*LANES)*7 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*6 + 8*lane) +: 8],
read_data_store[((DQ_BITS*LANES)*5 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*4 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*3 + 8*lane) +: 8],
read_data_store[((DQ_BITS*LANES)*2 + 8*lane) +: 8],read_data_store[((DQ_BITS*LANES)*1 + 8*lane) +: 8],read_data_store[((DQ_BITS*LANES)*0 + 8*lane) +: 8] }) begin
/* verilator lint_off WIDTH */
if(lane == LANES - 1) begin
/* verilator lint_on WIDTH */
state_calibrate <= BURST_WRITE;
end
else begin
lane <= lane + 1;
data_start_index[lane+1] <= 0;
end
end
else begin
data_start_index[lane] <= data_start_index[lane] + 8; //skip by 8
if(data_start_index[lane] == 56) begin //reached the end but no byte in write-pattern matches the data read, issue might be reading at wrong DQS toggle
data_start_index[lane] <= 0; //so we need to recalibrate the bitslip
start_index_check <= 0;
state_calibrate <= CHECK_STARTING_DATA;
end
end
//check if the data starts not at bit 0 (happens if the DQS toggles early than DQ, this means we are calibrated to read at same
//time as DQS toggles but since DQ is late then we need to look which DQS toggle does DQ actually start)
CHECK_STARTING_DATA: begin
if(read_lane_data[start_index_check +: 16] == write_pattern[0 +: 16]) begin //check if first
state_calibrate <= BITSLIP_DQS_TRAIN_3;
added_read_pipe[lane] <= { {( 4 - ($clog2(STORED_DQS_SIZE*8) - (3+1)) ){1'b0}} , dq_target_index[lane][$clog2(STORED_DQS_SIZE*8)-1:(3+1)] }
+ { 3'b0 , (dq_target_index[lane][3:0] >= (5+8)) };
dqs_bitslip_arrangement <= 16'b0011_1100_0011_1100 >> dq_target_index[lane][2:0];
state_calibrate <= BITSLIP_DQS_TRAIN_3;
end
else begin
start_index_check <= start_index_check + 16;
dq_target_index[lane] <= dq_target_index[lane] + 2;
if(dq_target_index[lane][$clog2(STORED_DQS_SIZE*8)] )begin //if last bit goes high, we are outside the possible values so we need to reset now
reset_from_calibrate <= 1;
end
end
end
BITSLIP_DQS_TRAIN_3: if(train_delay == 0) begin //train again the ISERDES to capture the DQ correctly
if(i_phy_iserdes_bitslip_reference[lane*serdes_ratio*2 +: 8] == dqs_bitslip_arrangement[7:0]) begin
state_calibrate <= ISSUE_WRITE_1; //finished bitslip calibration so we can now issue again new write and then read
added_read_pipe_max <= added_read_pipe_max > added_read_pipe[lane]? added_read_pipe_max:added_read_pipe[lane];
end
else begin
o_phy_bitslip[lane] <= 1;
train_delay <= 3;
end
end
/* WRITE_ZERO: if(!o_wb_stall_calib) begin //write zero to all addresses before starting write-read test
calib_stb <= 1;
calib_aux <= 2;
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= 1;
calib_addr <= write_test_address_counter[wb_addr_bits-1:0];
calib_data <= 0;
write_test_address_counter <= write_test_address_counter + 1;
if(MICRON_SIM) begin
if(write_test_address_counter[wb_addr_bits-1:0] == 999 ) begin
state_calibrate <= BURST_WRITE;
calib_stb <= 0;
calib_aux <= 0;
calib_we <= 0;
write_test_address_counter <= 0;
end
end
else begin
if(write_test_address_counter[wb_addr_bits-1:0] == {(wb_addr_bits){1'b1}} ) begin
state_calibrate <= BURST_WRITE;
calib_stb <= 0;
calib_aux <= 0;
calib_we <= 0;
write_test_address_counter <= 0;
end
end
end*/
BURST_WRITE: if(!o_wb_stall_calib) begin // Test 1: Burst write (per byte write to test datamask feature), then burst read
calib_stb <= 1;
calib_aux <= 2;
if(TDQS == 0) begin //Test datamask by writing 1 byte at a time
calib_sel <= 1 << write_by_byte_counter;
calib_we <= 1;
calib_addr <= write_test_address_counter[wb_addr_bits-1:0];
calib_data<= {wb_sel_bits{8'haa}};
calib_data[8*write_by_byte_counter +: 8] <= write_test_address_counter[7:0];
if(MICRON_SIM) begin
//if(write_test_address_counter[wb_addr_bits-1:0] == 500) begin //inject error at middle
// calib_data <= 1;
//end
if(write_by_byte_counter == {$clog2(wb_sel_bits){1'b1}}) begin
if(write_test_address_counter[wb_addr_bits-1:0] == 99 ) begin //MUST END AT ODD NUMBER
state_calibrate <= BURST_READ;
end
write_test_address_counter <= write_test_address_counter + 1;
end
end
else begin
//if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b00 , 1'b0, {(wb_addr_bits-3){1'b1}} }) begin //inject error at middle
// calib_data <= 1;
// end
if(write_by_byte_counter == {$clog2(wb_sel_bits){1'b1}}) begin
if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b00 , {(wb_addr_bits-2){1'b1}} } ) begin //MUST END AT ODD NUMBER
state_calibrate <= BURST_READ;
end
write_test_address_counter <= write_test_address_counter + 1;
end
end
write_by_byte_counter <= write_by_byte_counter + 1;
end
else begin // Straight burst to all bytes (all datamask on)
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= 1;
calib_addr <= write_test_address_counter[wb_addr_bits-1:0];
calib_data<= {wb_sel_bits{write_test_address_counter[7:0]}};
if(MICRON_SIM) begin
//if(write_test_address_counter[wb_addr_bits-1:0] == 500) begin //inject error at middle
// calib_data <= 1;
//end
if(write_test_address_counter[wb_addr_bits-1:0] == 99 ) begin //MUST END AT ODD NUMBER
state_calibrate <= BURST_READ;
end
end
else begin
//if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b00 , 1'b0, {(wb_addr_bits-3){1'b1}} }) begin //inject error at middle
// calib_data <= 1;
//end
if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b00 , {(wb_addr_bits-2){1'b1}} } ) begin //MUST END AT ODD NUMBER
state_calibrate <= BURST_READ;
end
end
write_test_address_counter <= write_test_address_counter + 1;
end
end
BURST_READ: if(!o_wb_stall_calib) begin
calib_stb <= 1;
calib_aux <= 3;
calib_we <= 0;
calib_addr <= read_test_address_counter;
read_test_address_counter <= read_test_address_counter + 1;
if(MICRON_SIM) begin
if(read_test_address_counter == 99) begin //MUST END AT ODD NUMBER
state_calibrate <= RANDOM_WRITE;
end
end
else begin
if(read_test_address_counter == { 2'b00 , {(wb_addr_bits-2){1'b1}} }) begin //MUST END AT ODD NUMBER
state_calibrate <= RANDOM_WRITE;
end
end
end
RANDOM_WRITE: if(!o_wb_stall_calib) begin // Test 2: Random write (increments row address to force precharge-act-r/w) then random read
calib_stb <= 1;
calib_aux <= 2;
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= 1;
calib_addr[ (ROW_BITS + BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (BA_BITS + COL_BITS- $clog2(serdes_ratio*2)) ]
<= write_test_address_counter[ROW_BITS-1:0];
calib_addr[(BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : 0]
<= write_test_address_counter[wb_addr_bits-1:ROW_BITS];
calib_data <= {wb_sel_bits{write_test_address_counter[7:0]}};
if(MICRON_SIM) begin
//if(write_test_address_counter[wb_addr_bits-1:0] == 1500) begin //inject error
// calib_data <= 1;
//end
if(write_test_address_counter[wb_addr_bits-1:0] == 199) begin //MUST END AT ODD NUMBER since ALTERNATE_WRITE_READ must start at even
state_calibrate <= RANDOM_READ;
end
end
else begin
// if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b01 , 1'b0, {(wb_addr_bits-3){1'b1}}} ) begin //inject error
// calib_data <= 1;
// end
if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b01 , {(wb_addr_bits-2){1'b1}} } ) begin //MUST END AT ODD NUMBER since ALTERNATE_WRITE_READ must start at even
state_calibrate <= RANDOM_READ;
end
end
write_test_address_counter <= write_test_address_counter + 1;
end
RANDOM_READ: if(!o_wb_stall_calib) begin
calib_stb <= 1;
calib_aux <= 3;
calib_we <= 0;
calib_addr[ (ROW_BITS + BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : (BA_BITS + COL_BITS- $clog2(serdes_ratio*2)) ]
<= read_test_address_counter[ROW_BITS-1:0];
calib_addr[(BA_BITS + COL_BITS- $clog2(serdes_ratio*2) - 1) : 0]
<= read_test_address_counter[wb_addr_bits-1:ROW_BITS];
read_test_address_counter <= read_test_address_counter + 1;
if(MICRON_SIM) begin
if(read_test_address_counter == 199) begin //MUST END AT ODD NUMBER since ALTERNATE_WRITE_READ must start at even
state_calibrate <= ALTERNATE_WRITE_READ;
end
end
else begin
if(read_test_address_counter == { 2'b01 , {(wb_addr_bits-2){1'b1}} } ) begin //MUST END AT ODD NUMBER since ALTERNATE_WRITE_READ must start at even
state_calibrate <= ALTERNATE_WRITE_READ;
end
end
end
ALTERNATE_WRITE_READ: if(!o_wb_stall_calib) begin
calib_stb <= 1;
calib_aux <= 4 + { {(AUX_WIDTH-1){1'b0}} , write_test_address_counter[0]}; //4 (write), 5 (read)
calib_sel <= {wb_sel_bits{1'b1}};
calib_we <= !write_test_address_counter[0]; //0(write) -> 1(read)
calib_addr <= {1'b0, write_test_address_counter[wb_addr_bits-1:1]}; //same address to be used for write and read ( so basically write then read instantly)
calib_data <= {wb_sel_bits{write_test_address_counter[7:0]}};
if(MICRON_SIM) begin
if(write_test_address_counter == 499) begin
train_delay <= 15;
state_calibrate <= FINISH_READ;
end
end
else begin
if(write_test_address_counter[wb_addr_bits-1:0] == { 2'b11 , {(wb_addr_bits-2){1'b1}} } ) begin
train_delay <= 15;
state_calibrate <= FINISH_READ;
end
end
write_test_address_counter <= write_test_address_counter + 1;
end
FINISH_READ: begin
calib_stb <= 0;
if(train_delay == 0) begin
state_calibrate <= DONE_CALIBRATE;
end
end
DONE_CALIBRATE: begin
calib_stb <= 0;
state_calibrate <= DONE_CALIBRATE;
already_finished_calibration <= 1;
end
endcase
`ifdef FORMAL_COVER
state_calibrate <= DONE_CALIBRATE;
`endif
read_lane_data <= {read_data_store[((DQ_BITS*LANES)*7 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*6 + 8*lane) +: 8],
read_data_store[((DQ_BITS*LANES)*5 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*4 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*3 + 8*lane) +: 8],
read_data_store[((DQ_BITS*LANES)*2 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*1 + 8*lane) +: 8], read_data_store[((DQ_BITS*LANES)*0 + 8*lane) +: 8] };
//maximum value has been reached and will go back to zero at next load
if(odelay_data_cntvaluein[lane] == 31) begin
odelay_cntvalue_repeated <= 1;
end
if(instruction_address == 19) begin //pre-stall delay to finish all remaining requests
pause_counter <= 1; // pause instruction address until pre-stall delay before refresh sequence finishes
//skip to instruction address 20 (precharge all before refresh) when no pending requests anymore
//toggle it for 1 clk cycle only
if( !stage1_pending && !stage2_pending && ( (o_wb_stall && state_calibrate == DONE_CALIBRATE) || (o_wb_stall_calib && state_calibrate != DONE_CALIBRATE) ) ) begin
pause_counter <= 0; // pre-stall delay done since all remaining requests are completed
end
end
if(repeat_test && state_calibrate == DONE_CALIBRATE) begin //can only repeat test once calibration is over
state_calibrate <= BURST_WRITE;
read_test_address_counter <= 0;
write_test_address_counter <= 0;
end
end
end
assign issue_read_command = (state_calibrate == MPR_READ && delay_before_read_data == 0);
assign o_phy_odelay_data_cntvaluein = odelay_data_cntvaluein[lane];
assign o_phy_odelay_dqs_cntvaluein = odelay_dqs_cntvaluein[lane];
assign o_phy_idelay_data_cntvaluein = idelay_data_cntvaluein[lane];
assign o_phy_idelay_dqs_cntvaluein = idelay_dqs_cntvaluein[lane];
assign dqs_target_index_value = dqs_start_index_stored[0]? dqs_start_index_stored + 2: dqs_start_index_stored + 1; // move to next odd (if 3 then 5, if 4 then 5)
// To show why next odd number is needed: https://github.com/AngeloJacobo/UberDDR3/tree/b762c464f6526159c1d8c2e4ee039b4ae4e78dbd#per-lane-read-calibration
reg[31:0] wb_data_to_wb2 = 0;
always @(posedge i_controller_clk) begin
if(o_wb_ack_read_q[0][0]) wb_data_to_wb2 <= o_wb_data[31:0]; //save data read
end
/*********************************************************************************************************************************************/
/******************************************************* Calibration Test Receiver *******************************************************/
reg[wb_data_bits-1:0] wrong_data = 0;
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
check_test_address_counter <= 0;
correct_read_data <= 0;
wrong_read_data <= 0;
reset_from_test <= 0;
end
else begin
reset_from_test <= 0;
if(state_calibrate != DONE_CALIBRATE) begin
if(o_wb_ack_read_q[0] == {{(AUX_WIDTH-3){1'b0}}, 3'd3, 1'b1}) begin //read ack received
if(o_wb_data == {wb_sel_bits{check_test_address_counter[7:0]}}) begin
correct_read_data <= correct_read_data + 1;
end
else begin
wrong_read_data <= wrong_read_data + 1;
wrong_data <= o_wb_data;
reset_from_test <= !already_finished_calibration; //reset controller when a wrong data is received (only when calibration is not yet done)
end
check_test_address_counter <= check_test_address_counter + 1;
end
else if(o_wb_ack_read_q[0] == {{(AUX_WIDTH-3){1'b0}}, 3'd5, 1'b1}) begin //read ack received (alternate write read)
if(o_wb_data == {wb_sel_bits{check_test_address_counter[7:0]}}) begin
correct_read_data <= correct_read_data + 1;
end
else begin
wrong_read_data <= wrong_read_data + 1;
wrong_data <= o_wb_data;
reset_from_test <= !already_finished_calibration; //reset controller when a wrong data is received (only when calibration is not yet done)
end
check_test_address_counter <= check_test_address_counter + 2;
end
end
if(repeat_test) begin
check_test_address_counter <= 0;
correct_read_data <= 0;
wrong_read_data <= 0;
end
end
end
/*********************************************************************************************************************************************/
/******************************************************* Wishbone 2 (PHY) Interface *******************************************************/
always @(posedge i_controller_clk) begin
if(sync_rst_wb2) begin
wb2_stb <= 0;
wb2_we <= 0; //data to be written which must have high i_wb2_sel are: {LANE_NUMBER, CNTVALUEIN}
wb2_addr <= 0;
wb2_data <= 0;
wb2_sel <= 0;
end
else begin
if( (i_wb2_cyc && SECOND_WISHBONE) && !o_wb2_stall) begin
wb2_stb <= i_wb2_stb;
wb2_we <= i_wb2_we; //data to be written which must have high i_wb2_sel are: {LANE_NUMBER, CNTVALUEIN}
wb2_addr <= i_wb2_addr;
wb2_data <= i_wb2_data;
wb2_sel <= i_wb2_sel;
end
else if(!o_wb2_stall) begin
wb2_stb <= 0;
wb2_we <= 0;
wb2_addr <= 0;
wb2_data <= 0;
wb2_sel <= 0;
end
end
end
always @(posedge i_controller_clk) begin
if(sync_rst_wb2) begin
wb2_phy_odelay_data_cntvaluein <= 0;
wb2_phy_odelay_data_ld <= 0;
wb2_phy_odelay_dqs_cntvaluein <= 0;
wb2_phy_odelay_dqs_ld <= 0;
wb2_phy_idelay_data_cntvaluein <= 0;
wb2_phy_idelay_data_ld <= 0;
wb2_phy_idelay_dqs_cntvaluein <= 0;
wb2_phy_idelay_dqs_ld <= 0;
wb2_update <= 0;
wb2_write_lane <= 0;
o_wb2_ack <= 0;
o_wb2_stall <= 1;
o_wb2_data <= 0;
reset_from_wb2 <= 0;
repeat_test <= 0;
end
else begin
wb2_phy_odelay_data_ld <= 0;
wb2_phy_odelay_dqs_ld <= 0;
wb2_phy_idelay_data_ld <= 0;
wb2_phy_idelay_dqs_ld <= 0;
wb2_update <= 0;
wb2_write_lane <= 0;
o_wb2_ack <= wb2_stb && (i_wb2_cyc && SECOND_WISHBONE); //always ack right after request
o_wb2_stall <= 0; //never stall
reset_from_wb2 <= 0;
repeat_test <= 0;
if(wb2_stb && (i_wb2_cyc && SECOND_WISHBONE)) begin
case(wb2_addr[4:0])
//read/write odelay cntvalue for DQ line
0: if(wb2_we) begin
wb2_phy_odelay_data_cntvaluein <= wb2_data[4:0]; //save first 5 bits as CNTVALUEIN for the ODELAYE2 for DQ
wb2_phy_odelay_data_ld <= 1 << (wb2_data[5 +: lanes_clog2]); //raise the lane to be loaded with new cntvaluein
wb2_update <= wb2_sel[$rtoi($ceil( (lanes_clog2 + 5)/8.0 )) - 1:0]; //only update when sel bit is high (data is valid)
end
else begin
o_wb2_data <= { {(WB2_DATA_BITS-5){1'b0}} , odelay_data_cntvaluein[wb2_addr[4 +: lanes_clog2]] };//use next bits of address as lane number to be read
end
//read/write odelay cntvalue for DQS line
1: if(wb2_we) begin
wb2_phy_odelay_dqs_cntvaluein <= wb2_data[4:0]; //save first 5 bits as CNTVALUEIN for the ODELAYE2 for DQS
wb2_phy_odelay_dqs_ld <= 1 << (wb2_data[5 +: lanes_clog2]); //raise the lane to be loaded with new cntvaluein
wb2_update <= wb2_sel[$rtoi($ceil( (lanes_clog2 + 5)/8.0 )) - 1:0]; //only update when sel bit is high (data is valid)
end
else begin
o_wb2_data <= { {(WB2_DATA_BITS-5){1'b0}} , odelay_dqs_cntvaluein[wb2_addr[4 +: lanes_clog2]] };//use next bits of address as lane number to be read
end
//read/write idelay cntvalue for DQ line
2: if(wb2_we) begin
wb2_phy_idelay_data_cntvaluein <= wb2_data[4:0]; //save first 5 bits as CNTVALUEIN for the IDELAYE2 for DQ
wb2_phy_idelay_data_ld <= 1 << (wb2_data[5 +: lanes_clog2]); //save next 5 bits for lane number to be loaded with new delay
wb2_update <= wb2_sel[$rtoi($ceil( (lanes_clog2 + 5)/8.0 )) - 1:0]; //only update when sel bit is high (data is valid)
end
else begin
o_wb2_data <= { {(WB2_DATA_BITS-5){1'b0}} , idelay_data_cntvaluein[wb2_addr[4 +: lanes_clog2]] }; //use next bits of address as lane number to be read
end
//read/write idelay cntvalue for DQS line
3: if(wb2_we) begin
wb2_phy_idelay_dqs_cntvaluein <= wb2_data[4:0]; //save first 5 bits as CNTVALUEIN for the IDELAYE2 for DQS
wb2_phy_idelay_dqs_ld <= 1 << (wb2_data[5 +: lanes_clog2]); //save next 5 bits for lane number to be loaded with new delay
wb2_update <= wb2_sel[$rtoi($ceil( (lanes_clog2 + 5)/8.0 )) - 1:0]; //only update when sel bit is high (data is valid)
end
else begin
o_wb2_data <= { {(WB2_DATA_BITS-5){1'b0}} , idelay_dqs_cntvaluein[wb2_addr[4 +: lanes_clog2]] }; //use next bits of address as lane number to be read
end
4: if(!wb2_we) begin
o_wb2_data[0] <= i_phy_idelayctrl_rdy; //1 bit, should be high when IDELAYE2 is ready
o_wb2_data[1 +: 6] <= state_calibrate; //5 bits, FSM state of the calibration sequence6
o_wb2_data[1 + 6 +: 5] <= instruction_address; //5 bits, address of the reset sequence
o_wb2_data[1 + 6 + 5 +: 4] <= added_read_pipe_max; //4 bit, max added read delay (must have a max value of 1)
end
5: if(!wb2_we) begin
for(index = 0; index < LANES; index = index + 1) begin
o_wb2_data[4*index +: 4] <= added_read_pipe[index];
end
//added read pipe delay for lanes 0-to-3 (4 bits each lane the max is just 1 for each)
end
/*
6: if(!wb2_we) begin
o_wb2_data <= dqs_store[31:0]; //show last 4 sets of received 8-bit DQS during MPR (repeated 4 times, must have a value of 10'b01_01_01_01_00 somewhere)
end
7: if(!wb2_we) begin
o_wb2_data <= wrong_data[31:0]; //lane 1
end
8: if(!wb2_we) begin
o_wb2_data <= wrong_data[63:32]; //first 32 bits of the data read after first write using the write_pattern 128'h80dbcfd275f12c3d_9177298cd0ad51c1
end
9: if(!wb2_we) begin
o_wb2_data <= wrong_data[95:64]; //first 32 bit of the patern written on the first write just for checking (128'h80dbcfd275f12c3d_9177298cd0ad51c1)
end
10: if(!wb2_we) begin //0x28 (data read back)
o_wb2_data <= wrong_data[127:96]; //first 32 bit of the patern written on the first write just for checking (128'h80dbcfd275f12c3d_9177298cd0ad51c1)
end
11: if(!wb2_we) begin //0x2c (data write)
o_wb2_data <= wrong_data[159:128]; //first 32 bit of the patern written on the first write just for checking (128'h80dbcfd275f12c3d_9177298cd0ad51c1)
end
12: if(!wb2_we) begin //0x30
o_wb2_data <= wrong_data[191:160]; //check if proper request is received
end
13: if(!wb2_we) begin //0x30
o_wb2_data <= wrong_data[223:192];//lane 1
end
14: if(!wb2_we) begin //0x30
o_wb2_data <= wrong_data[255:224]; //lane 1
end*/
15: if(!wb2_we) begin //0x30
o_wb2_data <= correct_read_data; //lane 1
end
16: if(!wb2_we) begin //0x30
o_wb2_data <= wrong_read_data; //lane 1
end
17: if(wb2_we) begin
repeat_test <= wb2_data[0];
reset_from_wb2 <= wb2_data[1];
end
18: if(!wb2_we) begin //0x30
o_wb2_data <= 32'h50; //lane 1
end
default: if(!wb2_we) begin //read
o_wb2_data <= {(WB2_DATA_BITS/2){2'b10}}; //return alternating 1s and 0s when address to be read is invalid
end
endcase
wb2_write_lane <= wb2_data[5 +: lanes_clog2]; //save next 5 bits for lane number to be loaded with new delay
end //end of if(wb2_stb)
end//end of else
end//end of always
// Logic connected to debug port
// Logic connected to debug port
wire debug_trigger;
assign o_debug1 = {27'd0, state_calibrate[4:0]};
assign o_debug2 = {debug_trigger,i_phy_iserdes_data[62:32]};
assign o_debug3 = {debug_trigger,i_phy_iserdes_data[30:0]};
assign debug_trigger = repeat_test /*o_wb_ack_read_q[0][0]*/;
(* mark_debug = "true" *) wire dq_all_zeroes;
assign dq_all_zeroes = (i_phy_iserdes_data == {(DQ_BITS*LANES*8){1'b0}});
/*********************************************************************************************************************************************/
/******************************************************* Functions *******************************************************/
//convert nanoseconds time input to number of controller clock cycles (referenced to CONTROLLER_CLK_PERIOD)
//output is set at same length as a MRS command (19 bits) to maximize the time slot
function [DELAY_SLOT_WIDTH - 1:0] ps_to_cycles ( input integer ps );
/* verilator lint_off WIDTHTRUNC */
ps_to_cycles = $rtoi( $ceil( ps*1.0/CONTROLLER_CLK_PERIOD ) );
/* verilator lint_on WIDTHTRUNC */
endfunction
//convert nCK input (number of DDR3 clock cycles) to number of controller clock cycles (referenced to serdes_ratio)
function [DELAY_SLOT_WIDTH - 1:0] nCK_to_cycles (input integer nCK);
/* verilator lint_off WIDTHTRUNC */
nCK_to_cycles = $rtoi( $ceil( nCK*1.0/serdes_ratio ) );
/* verilator lint_on WIDTHTRUNC */
endfunction
//convert nanoseconds time input to number of DDR clock cycles (referenced to DDR3_CLK_PERIOD)
function integer ps_to_nCK ( input integer ps );
ps_to_nCK = $rtoi( $ceil( ps*1.0/ DDR3_CLK_PERIOD ) );
endfunction
//convert DDR clock cycles to nanoseconds (referenced to DDR3_CLK_PERIOD)
function integer nCK_to_ps (input integer nCK);
nCK_to_ps = $rtoi( $ceil( nCK*1.0*DDR3_CLK_PERIOD ) );
endfunction
// functions used to infer some localparam values
function integer max(input integer a, input integer b);
if(a >= b) max = a;
else max = b;
endfunction
function integer max_int(input integer a, input integer b);
if(a >= b) max_int = a;
else max_int = b;
endfunction
//Find the 3-bit value for the Mode Register 0 WR (Write recovery for auto-precharge)
function[2:0] WRA_mode_register_value(input integer WRA);
//WR_min (write recovery for autoprecharge) in clock cycles is calculated by dividing tWR(in ns) by tCK(in ns) and rounding up to the next integer.
//The WR value in the mode register must be programmed to be equal or larger than WRmin.
case(WRA+1)
1,2,3,4,5: WRA_mode_register_value = 3'b001;
6: WRA_mode_register_value = 3'b010;
7: WRA_mode_register_value = 3'b011;
8: WRA_mode_register_value = 3'b100;
9,10: WRA_mode_register_value = 3'b101;
11,12: WRA_mode_register_value = 3'b110;
13,14: WRA_mode_register_value = 3'b111;
15,16: WRA_mode_register_value = 3'b000;
default: begin
WRA_mode_register_value = 3'b000; //defaulting to largest write recovery cycles: 16 cycles
end
endcase
endfunction
// Find the correct value for CL based on ddr3 clock period
function[3:0] CL_generator(input integer ddr3_clk_period);
begin
if(ddr3_clk_period <= 3_300 && ddr3_clk_period >= 3_000) begin
CL_generator = 4'd5;
end
else if(ddr3_clk_period <= 3_300 && ddr3_clk_period >= 2_500) begin
CL_generator = 4'd6;
end
else if(ddr3_clk_period <= 2_500 && ddr3_clk_period >= 1_875) begin
CL_generator = 4'd7;
end
else if(ddr3_clk_period <= 1_875 && ddr3_clk_period >= 1_500) begin
CL_generator = 4'd9;
end
else if(ddr3_clk_period <= 1_500 && ddr3_clk_period >= 1_250) begin
CL_generator = 4'd11;
end
end
endfunction
// Find the correct value for CWL based on ddr3 clock period
function[3:0] CWL_generator(input integer ddr3_clk_period);
begin
if(ddr3_clk_period <= 3_300 && ddr3_clk_period >= 3_000) begin
CWL_generator = 4'd5;
end
else if(ddr3_clk_period <= 3_300 && ddr3_clk_period >= 2_500) begin
CWL_generator = 4'd5;
end
else if(ddr3_clk_period <= 2_500 && ddr3_clk_period >= 1_875) begin
CWL_generator = 4'd6;
end
else if(ddr3_clk_period <= 1_875 && ddr3_clk_period >= 1_500) begin
CWL_generator = 4'd7;
end
else if(ddr3_clk_period <= 1_500 && ddr3_clk_period >= 1_250) begin
CWL_generator = 4'd8;
end
end
endfunction
function[1:0] get_slot (input[3:0] cmd); //cmd can either be CMD_PRE,CMD_ACT, CMD_WR, CMD_RD
integer delay;
reg[2:0] slot_number, read_slot, write_slot, anticipate_activate_slot, anticipate_precharge_slot;
reg[2:0] remaining_slot;
begin
// find read command slot number
delay = {{(32-4){1'b0}},CL_nCK};
for(slot_number = 0 ; delay != 0 ; delay = delay - 1) begin
slot_number = slot_number - 1'b1;
end
read_slot = slot_number;
// find write command slot number
delay = {{(32-4){1'b0}},CWL_nCK};
for(slot_number = 0 ; delay != 0; delay = delay - 1) begin
slot_number = slot_number - 1'b1;
end
write_slot = slot_number;
// find anticipate activate command slot number
if(CL_nCK > CWL_nCK) slot_number = read_slot;
else slot_number = write_slot;
delay = ps_to_nCK(tRCD);
for(slot_number = slot_number; delay != 0; delay = delay - 1) begin
slot_number = slot_number - 1'b1;
end
anticipate_activate_slot = slot_number;
// if computed anticipate_activate_slot is same with either write_slot or read_slot, decrement slot number until
while(anticipate_activate_slot == write_slot || anticipate_activate_slot == read_slot) begin
anticipate_activate_slot = anticipate_activate_slot - 1'b1;
end
//the remaining slot will be for precharge command
anticipate_precharge_slot = 0;
while(anticipate_precharge_slot == write_slot || anticipate_precharge_slot == read_slot || anticipate_precharge_slot == anticipate_activate_slot) begin
anticipate_precharge_slot = anticipate_precharge_slot - 1'b1;
end
//the remaining slot will be for precharge command
remaining_slot = 0;
while(remaining_slot == write_slot || remaining_slot == read_slot || remaining_slot == anticipate_activate_slot || remaining_slot == anticipate_precharge_slot) begin
remaining_slot = remaining_slot + 1'b1;
end
case(cmd)
CMD_RD: get_slot = read_slot[1:0];
CMD_WR: get_slot = write_slot[1:0];
CMD_ACT: get_slot = anticipate_activate_slot[1:0];
CMD_PRE: get_slot = anticipate_precharge_slot[1:0];
0: get_slot = remaining_slot[1:0];
default: begin
`ifdef FORMAL
assert(0); //force FORMAL to fail if this is ever reached
`endif
end
endcase
end
endfunction
//find the delay to be used by delay_before_xxxx_counter.
// - delay_nCK = delay required between the two commands in DDR3 clock cycles
// - start_slot = slot number of the first command
// - end_slot = slot number of the second command
// returns the number of controller clock cycles to satisfy the delay required between the two commands
function [3:0] find_delay(input integer delay_nCK, input reg[1:0] start_slot, input reg[1:0] end_slot);
integer k; //error: variable declaration assignments are only allowed at the module level
begin
k = 0;
/* verilator lint_off WIDTH */
while( ((4 - start_slot) + end_slot + 4*k) < delay_nCK) begin
/* verilator lint_on WIDTH */
k = k + 1;
end
find_delay = k[3:0];
end
endfunction
/*********************************************************************************************************************************************/
`ifndef YOSYS
///YOSYS: System task `$display' called with invalid/unsupported format specifier
initial begin
$display("\nCONTROLLER PARAMETERS:\n-----------------------------");
$display("CONTROLLER_CLK_PERIOD = %0d", CONTROLLER_CLK_PERIOD);
$display("DDR3_CLK_PERIOD = %0d", DDR3_CLK_PERIOD);
$display("ROW_BITS = %0d", ROW_BITS);
$display("COL_BITS = %0d", COL_BITS);
$display("BA_BITS = %0d", BA_BITS);
$display("BYTE_LANES = %0d", LANES);
$display("AUX_WIDTH = %0d", AUX_WIDTH);
$display("MICRON_SIM = %0d", MICRON_SIM);
$display("ODELAY_SUPPORTED = %0d", ODELAY_SUPPORTED);
$display("SECOND_WISHBONE = %0d", SECOND_WISHBONE);
$display("WB2_ADDR_BITS = %0d", WB2_ADDR_BITS);
$display("WB2_DATA_BITS = %0d", WB2_DATA_BITS);
$display("\nCONTROLLER LOCALPARAMS:\n-----------------------------");
$display("wb_addr_bits = %0d", wb_addr_bits);
$display("wb_data_bits = %0d", wb_data_bits);
$display("wb_sel_bits = %0d", wb_sel_bits);
$display("wb2_sel_bits = %0d", wb2_sel_bits);
$display("DQ_BITS = %0d", DQ_BITS);
$display("\nCOMMAND SLOTS:\n-----------------------------");
$display("READ_SLOT = %0d", READ_SLOT);
$display("WRITE_SLOT = %0d", WRITE_SLOT);
$display("ACTIVATE_SLOT = %0d", ACTIVATE_SLOT);
$display("PRECHARGE_SLOT = %0d", PRECHARGE_SLOT);
$display("REMAINING_SLOT = %0d", REMAINING_SLOT);
$display("\nDELAYS:\n-----------------------------");
$display("CL = %0d", CL_nCK);
$display("CWL = %0d", CWL_nCK);
$display("PRECHARGE_TO_ACTIVATE_DELAY = %0d", PRECHARGE_TO_ACTIVATE_DELAY);
$display("ACTIVATE_TO_WRITE_DELAY = %0d", ACTIVATE_TO_WRITE_DELAY);
$display("ACTIVATE_TO_READ_DELAY = %0d", ACTIVATE_TO_READ_DELAY);
$display("ACTIVATE_TO_PRECHARGE_DELAY = %0d", ACTIVATE_TO_PRECHARGE_DELAY);
$display("READ_TO_WRITE_DELAY = %0d", READ_TO_WRITE_DELAY);
$display("READ_TO_READ_DELAY = %0d", READ_TO_READ_DELAY);
$display("READ_TO_PRECHARGE_DELAY = %0d", READ_TO_PRECHARGE_DELAY);
$display("WRITE_TO_WRITE_DELAY = %0d", WRITE_TO_WRITE_DELAY);
$display("WRITE_TO_READ_DELAY = %0d", WRITE_TO_READ_DELAY);
$display("WRITE_TO_PRECHARGE_DELAY = %0d", WRITE_TO_PRECHARGE_DELAY);
$display("STAGE2_DATA_DEPTH = %0d", STAGE2_DATA_DEPTH);
$display("READ_ACK_PIPE_WIDTH = %0d\n", READ_ACK_PIPE_WIDTH);
end
`endif
`ifdef FORMAL
`define TEST_CONTROLLER_PIPELINE
`ifdef FORMAL_COVER
initial assume(!i_rst_n);
reg[24:0] f_wb_inputs[31:0];
reg[9:0] f_reset_counter = 0;
reg[4:0] f_index = 0;
reg f_past_valid = 0;
initial begin
/*
// Sequential read to row 0 then jump to row 2
f_wb_inputs[0] = {1'b0, {14'd0,3'd1, 7'd0}}; //read
f_wb_inputs[1] = {1'b0, {14'd0,3'd1, 7'd1}}; //read on same bank (tCCD)
f_wb_inputs[2] = {1'b0, {14'd0,3'd1, 7'd2}}; //write on same bank (tRTW)
f_wb_inputs[3] = {1'b0, {14'd0,3'd1, 7'd3}}; //write on same bank (tCCD)
f_wb_inputs[4] = {1'b0, {14'd0,3'd1, 7'd4}}; //read on different bank
f_wb_inputs[5] = {1'b0, {14'd0,3'd1, 7'd5}}; //write on same bank (tRTW)
f_wb_inputs[6] = {1'b0, {14'd2,3'd1, 7'd6}}; //write on different bank (already activated)
f_wb_inputs[7] = {1'b0, {14'd2,3'd1, 7'd7}}; //write (tCCD)
f_wb_inputs[8] = {1'b0, {14'd2,3'd1, 7'd8}}; //write on different bank (already activated but wrong row)
f_wb_inputs[9] = {1'b0, {14'd2,3'd1, 7'd9}}; //write (tCCD)
f_wb_inputs[10] = {1'b0, {14'd3,3'd1, 7'd10}}; //write (tCCD)
f_wb_inputs[11] = {1'b0, {14'd3,3'd1, 7'd11}}; //read (same bank but wrong row so precharge first)
f_wb_inputs[12] = {1'b0, {14'd3,3'd1, 7'd12}}; //read (tCCD)
f_wb_inputs[13] = {1'b0, {14'd3,3'd1, 7'd13}}; //read (tCCD)
*/
f_wb_inputs[0] = {1'b0, {14'd0,3'd1, 7'd0}}; //read
f_wb_inputs[1] = {1'b0, {14'd0,3'd1, 7'd1}}; //read on same bank (tCCD)
f_wb_inputs[2] = {1'b1, {14'd0,3'd1, 7'd2}}; //write on same bank (tRTW)
f_wb_inputs[3] = {1'b1, {14'd0,3'd1, 7'd3}}; //write on same bank (tCCD)
f_wb_inputs[4] = {1'b0, {14'd0,3'd2, 7'd0}}; //read on different bank
f_wb_inputs[5] = {1'b1, {14'd0,3'd2, 7'd1}}; //write on same bank (tRTW)
f_wb_inputs[6] = {1'b1, {14'd0,3'd1, 7'd4}}; //write on different bank (already activated)
f_wb_inputs[7] = {1'b1, {14'd0,3'd1, 7'd5}}; //write (tCCD)
f_wb_inputs[8] = {1'b1, {14'd1,3'd2, 7'd0}}; //write on different bank (already activated but wrong row)
f_wb_inputs[9] = {1'b1, {14'd1,3'd2, 7'd1}}; //write (tCCD)
f_wb_inputs[10] = {1'b1, {14'd1,3'd2, 7'd2}}; //write (tCCD)
f_wb_inputs[11] = {1'b0, {14'd2,3'd2, 7'd0}}; //read (same bank but wrong row so precharge first)
f_wb_inputs[12] = {1'b0, {14'd2,3'd2, 7'd1}}; //read (tCCD)
f_wb_inputs[13] = {1'b0, {14'd2,3'd2, 7'd2}}; //read (tCCD)
/*
f_wb_inputs[0] = {1'b0, {14'd0,3'd1, 7'd0}}; //read
f_wb_inputs[1] = {1'b0, {14'd0,3'd1, 7'd1}}; //read on same bank (tCCD)
f_wb_inputs[2] = {1'b1, {14'd0,3'd2, 7'd0}}; //write on the anticipated bank
f_wb_inputs[3] = {1'b1, {14'd0,3'd2, 7'd1}}; //write on same bank (tCCD)
f_wb_inputs[4] = {1'b0, {14'd0,3'd3, 7'd0}}; //read on the anticipated bank
f_wb_inputs[5] = {1'b0, {14'd0,3'd3, 7'd1}}; //read on same bank (tCCD)
f_wb_inputs[6] = {1'b1, {14'd0,3'd7, 7'd0}}; //write on the un-anticipated idle bank (activate first)
f_wb_inputs[7] = {1'b1, {14'd0,3'd1, 7'd1}}; //write on the un-anticipated active bank and row (write)
f_wb_inputs[8] = {1'b1, {14'd1,3'd7, 7'd0}}; //write on the un-anticipated active bank but wrong row (precharge first)
*/
/*
f_wb_inputs[0] = {1'b0, {14'd0,3'd1, 7'd0}}; //read
f_wb_inputs[1] = {1'b0, {14'd0,3'd1, 7'd1}}; //read
f_wb_inputs[2] = {1'b0, {14'd0,3'd1, 7'd2}}; //read
f_wb_inputs[3] = {1'b0, {14'd0,3'd1, 7'd3}}; //read
f_wb_inputs[4] = {1'b0, {14'd0,3'd1, 7'd4}}; //read
f_wb_inputs[5] = {1'b0, {14'd0,3'd1, 7'd5}}; //read
f_wb_inputs[6] = {1'b0, {14'd0,3'd1, 7'd6}}; //write
f_wb_inputs[7] = {1'b0, {14'd0,3'd1, 7'd7}}; //write
f_wb_inputs[8] = {1'b0, {14'd0,3'd1, 7'd8}}; //write
f_wb_inputs[9] = {1'b0, {14'd0,3'd1, 7'd9}}; //write
f_wb_inputs[10] = {1'b0, {14'd0,3'd1, 7'd10}}; //write
f_wb_inputs[11] = {1'b0, {14'd0,3'd1, 7'd11}}; //write
*/
/*
f_wb_inputs[0] = {1'b0, {14'd1,3'd1, 7'd120}}; //write on same bank (tRTW)
f_wb_inputs[1] = {1'b0, {14'd1,3'd1, 7'd121}}; //write on different bank (already activated)
f_wb_inputs[2] = {1'b0, {14'd1,3'd1, 7'd122}}; //write (tCCD)
f_wb_inputs[3] = {1'b0, {14'd1,3'd1, 7'd123}}; //write on different bank (already activated but wrong row)
f_wb_inputs[4] = {1'b0, {14'd1,3'd1, 7'd124}}; //write (tCCD)
f_wb_inputs[5] = {1'b0, {14'd1,3'd1, 7'd125}}; //write (tCCD)
f_wb_inputs[6] = {1'b0, {14'd1,3'd1, 7'd126}}; //read (same bank but wrong row so precharge first)
f_wb_inputs[7] = {1'b0, {14'd1,3'd1, 7'd127}}; //read (tCCD)
f_wb_inputs[8] = {1'b0, {14'd1,3'd2, 7'd0}}; //read (tCCD)
f_wb_inputs[9] = {1'b0, {14'd1,3'd2, 7'd1}}; //read (tCCD)
f_wb_inputs[10] = {1'b0, {14'd1,3'd2, 7'd2}}; //read (tCCD)
*/
end
initial begin
f_reset_counter = 0;
end
always @(posedge i_controller_clk) begin
if(!o_wb_stall) begin
f_index <= f_index + 1; //number of requests accepted
end
f_reset_counter <= f_reset_counter + 1;
end
always @(posedge i_controller_clk) begin
assume(i_wb_cyc == 1);
assume(i_wb_stb == 1);
if(f_past_valid) begin
assume(i_rst_n);
end
assume(i_wb_we == f_wb_inputs[f_index][24]);
assume(i_wb_addr == f_wb_inputs[f_index][23:0]);
cover(f_index == 10);
if(f_index != 0) begin
assume(i_rst_n); //dont reset just to skip a request forcefully
end
end
`endif //endif for FORMAL_COVER
`ifdef TEST_CONTROLLER_PIPELINE
// wires and registers used in this formal section
`ifdef TEST_DATA
localparam F_TEST_CMD_DATA_WIDTH = $bits(i_wb_data) + $bits(i_wb_sel) + $bits(i_aux) + $bits(i_wb_addr) + $bits(i_wb_we);
`else
localparam F_TEST_CMD_DATA_WIDTH = $bits(i_wb_addr) + $bits(i_wb_we);
`endif
localparam F_MAX_STALL = max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY) + 1 + PRECHARGE_TO_ACTIVATE_DELAY + 1 + max(ACTIVATE_TO_WRITE_DELAY,ACTIVATE_TO_READ_DELAY) + 1 ;
//worst case delay (Precharge -> Activate-> R/W)
//add 1 to each delay since they end at zero
localparam F_MAX_ACK_DELAY = F_MAX_STALL + (READ_ACK_PIPE_WIDTH + 2); //max_stall + size of shift_reg_read_pipe_q + o_wb_ack_read_q (assume to be two via read_pipe_max)
(*keep*) wire[3:0] f_max_stall, f_max_ack_delay;
assign f_max_stall = F_MAX_STALL;
assign f_max_ack_delay = F_MAX_ACK_DELAY;
reg f_past_valid = 0;
reg[$bits(instruction_address) - 1: 0] f_addr = 0, f_read = 0 ;
reg[$bits(instruction) - 1:0] f_read_inst = INITIAL_RESET_INSTRUCTION;
reg[3:0] f_count_refreshes = 0; //count how many refresh cycles had already passed
reg[24:0] f_wb_inputs[31:0];
reg[4:0] f_index = 0;
reg[5:0] f_counter = 0;
reg[4:0] f_index_1;
reg[F_TEST_CMD_DATA_WIDTH - 1:0] f_write_data;
reg f_write_fifo = 0, f_read_fifo = 0;
reg[ROW_BITS-1:0] f_bank_active_row[(1<<BA_BITS)-1:0];
reg[(1<<BA_BITS)-1:0] f_bank_status = 0;
(*keep*) reg[(1<<BA_BITS)-1:0] f_bank_status_2 = 0;
wire f_empty, f_full;
wire[F_TEST_CMD_DATA_WIDTH - 1:0] f_read_data;
wire[F_TEST_CMD_DATA_WIDTH - 1:0] f_read_data_next;
wire[$bits(instruction) - 1:0] a= read_rom_instruction(f_const_addr); //retrieve an instruction based on engine's choice
wire[1:0] f_write_slot;
wire[1:0] f_read_slot;
wire[1:0] f_precharge_slot;
wire[1:0] f_activate_slot;
(*anyconst*) reg[$bits(instruction_address) - 1: 0] f_const_addr;
initial assume(!i_rst_n);
reg past_sync_rst_controller = 1;
always @(posedge i_controller_clk) begin
past_sync_rst_controller <= sync_rst_controller;
end
always @* begin
//assert(tMOD + tZQinit > nCK_to_cycles(tDLLK)); //Initialization sequence requires that tDLLK is satisfied after MRS to mode register 0 and ZQ calibration
assert(MR0[18] != 1'b1); //last Mode Register bit should never be zero
assert(MR1_WL_EN[18] != 1'b1); //(as this is used for A10-AP control for non-MRS
assert(MR1_WL_DIS[18] != 1'b1); //(as this is used for A10-AP control for non-MRS
assert(MR2[18] != 1'b1); //commands in the reset sequence)
assert(MR3_MPR_EN[18] != 1'b1);
assert(MR3_MPR_DIS[18] != 1'b1);
assert(DELAY_COUNTER_WIDTH <= $bits(MR0)); //bitwidth of mode register should be enough for the delay counter
//sanity checking to ensure 5 bits is allotted for extra instruction {reset_finished, use_timer , stay_command , cke , reset_n }
assert(($bits(instruction) - $bits(CMD_MRS) - $bits(MR0)) == 5 );
assert(DELAY_SLOT_WIDTH >= DELAY_COUNTER_WIDTH); //width occupied by delay timer slot on the reset rom must be able to occupy the maximum possible delay value on the reset sequence
end
always @(posedge i_controller_clk) f_past_valid <= 1;
//The idea below is sourced from https://zipcpu.com/formal/2019/11/18/genuctrlr.html
//We will form a packet of information describing each instruction as it goes through the pipeline and make assertions along the way.
//2-stage Pipeline: f_addr (update address) -> f_read (read instruction from rom)
//pipeline stage logic: f_addr (update address) -> f_read (read instruction from rom)
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
f_addr <= 0;
f_read <= 0;
end
//move the pipeline forward when counter is about to go zero and we are not yet at end of reset sequence
else if((delay_counter == 1 || !instruction[USE_TIMER])) begin
f_addr <= (f_addr == 22)? 19:f_addr + 1;
f_read <= f_addr;
end
end
// assert f_addr and f_read as shadows of next and current instruction address
always @* begin
assert(f_addr == instruction_address); //f_addr is the shadow of instruction_address (thus f_addr is the address of NEXT instruction)
f_read_inst = read_rom_instruction(f_read); //f_read is the address of CURRENT instruction
assert(f_read_inst == read_rom_instruction(f_read)); // needed for induction to make sure the engine will not create his own instruction
if(f_addr == 0) begin
f_read_inst = INITIAL_RESET_INSTRUCTION; //will only happen at the very start: f_addr (0) -> f_read (0) where we are reading the initial reset instruction and not the rom
end
assert(f_read_inst == instruction); // f_read_inst is the shadow of current instruction
end
// main assertions for the reset sequence
always @(posedge i_controller_clk) begin
if(past_sync_rst_controller) begin
assert(f_addr == 0);
assert(f_read == 0);
assert(instruction_address == 0);
assert(delay_counter == (INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0]));
assert(delay_counter_is_zero == (INITIAL_RESET_INSTRUCTION[DELAY_COUNTER_WIDTH - 1:0] == 0));
end
else if(f_past_valid) begin
//if counter is zero previously and current instruction needs timer delay, then this cycle should now have the new updated counter value
if( $past(delay_counter_is_zero) && $past(f_read_inst[USE_TIMER]) ) begin
assert(delay_counter == f_read_inst[DELAY_COUNTER_WIDTH - 1:0]);
end
//delay_counter_is_zero can be high when counter is zero and current instruction needs delay
if($past(f_read_inst[USE_TIMER]) && !$past(pause_counter) ) begin
assert( delay_counter_is_zero == (delay_counter == 0) );
end
//delay_counter_is_zero will go high this cycle when we received a don't-use-timer instruction
else if(!$past(f_read_inst[USE_TIMER]) && !$past(pause_counter)) begin
assert(delay_counter_is_zero);
end
//we are on the middle of a delay thus all values must remain constant while only delay_counter changes (decrement)
if(!delay_counter_is_zero) begin
assert(f_addr == $past(f_addr));
assert(f_read == $past(f_read));
assert(f_read_inst == $past(f_read_inst));
end
//if delay is not yet zero and timer delay is enabled, then delay_counter should decrement
if(!$past(delay_counter_is_zero) && $past(f_read_inst[USE_TIMER]) && !$past(pause_counter) ) begin
assert(delay_counter == $past(delay_counter) - 1);
assert(delay_counter < $past(delay_counter) ); //just to make sure delay_counter will never overflow back to all 1's
end
//sanity checking for the comment "delay_counter will be zero AT NEXT CLOCK CYCLE when counter is now one"
if($past(delay_counter) == 1) begin
assert(delay_counter == 0 && delay_counter_is_zero);
end
//assert the relationship between the stages FOR RESET SEQUENCE
if(!reset_done) begin
if(f_addr == 0) begin
assert(f_read == 0); //will only happen at the very start: f_addr (0) -> f_read (0)
end
else if(f_read == 0) begin
assert(f_addr <= 1); //will only happen at the very first two cycles: f_addr (1) -> f_read (0) or f_addr (0) -> f_read (0)
end
//else if($past(reset_done)) assert(f_read == $past(f_read)); //reset instruction does not repeat after reaching end address thus it must saturate when pipeline reaches end
else begin
assert(f_read + 1 == f_addr); //address increments continuously
end
assert($past(f_read) < 21); //only instruction address 0-to-13 is for reset sequence (reset_done is asserted at address 14)
end
//assert the relationship between the stages FOR REFRESH SEQUENCE
else begin
if(f_read == 22) begin
assert(f_addr == 19); //if current instruction is 22, then next instruction must be at 19 (instruction address wraps from 15 to 12)
end
else if(f_addr == 19) begin
assert(f_read == 22); //if next instruction is at 12, then current instruction must be at 15 (instruction address wraps from 15 to 12)
end
else begin
assert(f_read + 1 == f_addr); //if there is no need to wrap around, then instruction address must increment
end
assert((f_read >= 19 && f_read <= 22) ); //refresh sequence is only on instruction address 19,20,21,22
end
// reset_done must retain high when it was already asserted once
if($past(reset_done)) begin
assert(reset_done);
end
// reset is already done at address 21 and up
if($past(f_read) >= 21 ) begin
assert(reset_done);
end
//if reset is done, the REF_IDLE must only be high at instruction address 14 (on the middle of tREFI)
if(reset_done && f_read_inst[REF_IDLE]) begin
assert(f_read == 21);
end
end
end
// assertions on the instructions stored on the rom
always @* begin
//there MUST BE no instruction which USE_TIMER is high but delay is zero since it can cause the logic to lock-up (delay must be at least 1)
if(a[USE_TIMER]) begin
assert( a[DELAY_COUNTER_WIDTH - 1:0] > 0);
end
end
// assertion on FSM calibration
always @* begin
if(instruction_address < 13) begin
assert(state_calibrate == IDLE);
end
if(state_calibrate > IDLE && state_calibrate <= BITSLIP_DQS_TRAIN_2) begin
assert(instruction_address == 13);
assert(pause_counter);
end
if(state_calibrate > START_WRITE_LEVEL && state_calibrate <= WAIT_FOR_FEEDBACK) begin
assert(instruction_address == 17);
assert(pause_counter);
end
if(pause_counter) begin
assert(delay_counter != 0);
end
if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= ANALYZE_DATA) begin
assume(instruction_address == 22); //write-then-read calibration will not take more than tREFI (7.8us, delay a address 22)
assert(reset_done);
end
if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= DONE_CALIBRATE) begin
assert(reset_done);
end
if(state_calibrate == DONE_CALIBRATE) begin
assert(reset_done);
assert(instruction_address >= 19);
end
if(reset_done) begin
assert(instruction_address >= 19);
end
assume(repeat_test == 0);
end
always @* begin
//make sure each command has distinct slot number (except for read/write which can have the same or different slot number)
//assert((WRITE_SLOT != ACTIVATE_SLOT != PRECHARGE_SLOT) && (READ_SLOT != ACTIVATE_SLOT != PRECHARGE_SLOT) );
assert(WRITE_SLOT != ACTIVATE_SLOT);
assert(WRITE_SLOT != PRECHARGE_SLOT);
assert(READ_SLOT != ACTIVATE_SLOT);
assert(READ_SLOT != PRECHARGE_SLOT);
//make sure slot number for read command is correct
end
//create a formal assertion that says during refresh ack should be low always
//make an assertion that there will be no request pending before actual refresh starts at instruction 4'd12
mini_fifo #(
.FIFO_WIDTH(1), //the fifo will have 2**FIFO_WIDTH positions
.DATA_WIDTH(F_TEST_CMD_DATA_WIDTH) //each FIFO position can store DATA_WIDTH bits
) fifo_1 (
.i_clk(i_controller_clk),
.i_rst_n(!past_sync_rst_controller && i_wb_cyc), //reset outstanding request at reset or when cyc goes low
.read_fifo(f_read_fifo),
.write_fifo(f_write_fifo),
.empty(f_empty),
.full(f_full),
.write_data(f_write_data),
.read_data(f_read_data),
.read_data_next(f_read_data_next)
);
always @* begin
if(state_calibrate == DONE_CALIBRATE && i_wb_cyc) begin
if(f_full) begin
assert(stage1_pending && stage2_pending);//there are 2 contents
end
if(stage1_pending && stage2_pending) begin
assert(f_full);
end
if(!f_empty && !f_full) begin
assert(stage1_pending ^ stage2_pending);//there is 1 content
end
if(stage1_pending ^ stage2_pending) begin
assert(!f_empty && !f_full);
end
if(f_empty) begin
assert(stage1_pending == 0 && stage2_pending==0); //there is 0 content
end
if(stage1_pending == 0 && stage2_pending == 0) begin
assert(f_empty);
end
end
if(state_calibrate < ISSUE_WRITE_1) begin
assert(!stage1_pending && !stage2_pending);
end
if(stage1_pending && state_calibrate == ISSUE_READ) begin
assert(stage1_we);
end
if(stage2_pending && state_calibrate == ISSUE_READ) begin
assert(stage2_we);
end
if(state_calibrate == ANALYZE_DATA) begin
assert(!stage1_pending && !stage2_pending);
end
if(state_calibrate == READ_DATA && calib_stb) begin //if read request is not yet sent, the stage we must both be writes
if(stage1_pending) begin
assert(stage1_we);
end
if(stage2_pending) begin
assert(stage2_we);
end
assert(f_sum_of_pending_acks <= 2);
end
if(state_calibrate == READ_DATA && !calib_stb) begin //if read request is not yet sent, the stage we must both be writes
if(stage1_pending && !stage2_pending) begin
assert(!stage1_we);
end
if(!stage1_pending && stage2_pending) begin
assert(!stage2_we);
end
if(stage1_pending && stage2_pending) begin
assert(!stage1_we);
assert(stage2_we);
end
end
assume(state_calibrate != CHECK_STARTING_DATA && state_calibrate != BITSLIP_DQS_TRAIN_3); //this state should not be used (only for ddr3 with problems on DQ-DQS alignment)
end
always @(posedge i_controller_clk) begin
if(f_past_valid) begin
//switch from calibrate to done
if(state_calibrate == DONE_CALIBRATE && $past(state_calibrate) != DONE_CALIBRATE) begin
//assert($past(state_calibrate) == FINISH_READ);
assert($past(state_calibrate) == FINISH_READ);
assert(f_empty);
assert(!stage1_pending);
assert(!stage2_pending);
//assert(f_bank_status == 1); //only first bank is activated
//assert(bank_status_q == 1);
end
if(stage1_pending /*&& $past(state_calibrate) == READ_DATA */ && state_calibrate == READ_DATA && !calib_stb) begin
assert(!stage1_we);
end
//if(instruction_address == 21 || ($past(instruction_address) == 20 && $past(instruction_address,2) == 19) || instruction_address < 19) begin //calibration
// assert(f_bank_status == 0);
// assert(bank_status_q == 0);
// end
if(!reset_done) begin
assert(f_bank_status == 0);
assert(bank_status_q == 0);
end
/*if(state_calibrate <= ANALYZE_DATA) begin
assert(f_bank_status == 0 || f_bank_status == 1); //only first bank is activated
assert(bank_status_q == 0 || f_bank_status == 1);
end*/
end
end
//wishbone request should have a corresponding DDR3 command at the output
//wishbone request will be written to fifo, then once a DDR3 command is
//issued the fifo will be read to check if the DDR3 command matches the
//corresponding wishbone request
reg[ROW_BITS-1:0] f_read_data_col;
reg[BA_BITS-1:0] f_read_data_bank;
reg[AUX_WIDTH-1:0] f_read_data_aux;
reg[wb_sel_bits-1:0] f_read_data_wb_sel;
always @* begin
//write the wb request to fifo
if(i_wb_stb && i_wb_cyc && !o_wb_stall && state_calibrate == DONE_CALIBRATE) begin
f_write_fifo = 1;
`ifdef TEST_DATA
f_write_data = {i_wb_data, i_wb_sel, i_aux, i_wb_addr,i_wb_we};
`else
f_write_data = {i_wb_addr,i_wb_we};
`endif
end
else begin
f_write_fifo = 0;
end
f_read_fifo = 0;
//check if a DDR3 command is issued
if(i_wb_cyc) begin //only if already done calibrate and controller can accept wb request
if(cmd_d[WRITE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0100) begin //WRITE
if(state_calibrate == DONE_CALIBRATE) begin
assert(f_bank_status[cmd_d[WRITE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == 1'b1); //the bank that will be written must initially be active
f_read_data_col = {f_read_data[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}; //column address must match
assert(cmd_d[WRITE_SLOT][CMD_ADDRESS_START:0] == f_read_data_col);
f_read_data_bank = f_read_data[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]; //bank must match
assert(cmd_d[WRITE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1] == f_read_data_bank);
`ifdef TEST_DATA
f_read_data_aux = f_read_data[$bits(i_wb_addr) + 1 +: AUX_WIDTH]; //UAX ID must match
assert(stage2_aux == f_read_data_aux);
f_read_data_wb_sel = (f_read_data[$bits(i_wb_addr) + AUX_WIDTH + 1 +: $bits(i_wb_sel)]);
assert(stage2_dm_unaligned == ~f_read_data_wb_sel); //data mask mst match inverse of wb sel
assert(stage2_data_unaligned == f_read_data[$bits(i_wb_sel) + $bits(i_wb_addr) + AUX_WIDTH + 1 +: $bits(i_wb_data)]); //actual data must match
`endif
assert(f_read_data[0]); //i_wb_we must be high
f_read_fifo = 1; //advance read pointer to prepare for next read
end
else if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= ANALYZE_DATA) begin
assert(stage2_aux == 0);
end
//assert(f_bank_active_row[cmd_d[WRITE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == current_row); //column to be written must be the current active row
end
if(cmd_d[READ_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0101) begin //READ
if(state_calibrate == DONE_CALIBRATE) begin
assert(f_bank_status[cmd_d[READ_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == 1'b1); //the bank that will be read must initially be active
f_read_data_col = {f_read_data[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}; //column address must match
assert(cmd_d[READ_SLOT][CMD_ADDRESS_START:0] == f_read_data_col);
f_read_data_bank = f_read_data[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]; //bank must match
assert(cmd_d[READ_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1] == f_read_data_bank);
`ifdef TEST_DATA
f_read_data_aux = f_read_data[$bits(i_wb_addr) + 1 +: AUX_WIDTH]; //UAX ID must match
assert(stage2_aux == f_read_data_aux);
`endif
assert(!f_read_data[0]); //i_wb_we must be low
f_read_fifo = 1; //advance read pointer to prepare for next read
end
else if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= ANALYZE_DATA) begin
assert(stage2_aux == 1);
end
//assert(f_bank_active_row[cmd_d[READ_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == current_row);//column to be written must be the current active row
end
if(cmd_d[PRECHARGE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0010) begin //PRECHARGE
if(state_calibrate == DONE_CALIBRATE && (instruction_address == 22 || instruction_address == 19)) begin
assert(f_bank_status[cmd_d[PRECHARGE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == 1'b1); //the bank that should be precharged must initially be active
end
end
if(cmd_d[ACTIVATE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0011) begin //ACTIVATE
if(state_calibrate == DONE_CALIBRATE) begin
assert(f_bank_status[cmd_d[ACTIVATE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] == 1'b0); //the bank that should be activated must initially be precharged
end
end
if(reset_done) begin
assert(cmd_d[PRECHARGE_SLOT][CMD_CKE] && cmd_d[PRECHARGE_SLOT][CMD_RESET_N]); //cke and rst_n should stay high when reset sequence is already done
assert(cmd_d[ACTIVATE_SLOT][CMD_CKE] && cmd_d[ACTIVATE_SLOT][CMD_RESET_N]); //cke and rst_n should stay high when reset sequence is already done
assert(cmd_d[READ_SLOT][CMD_CKE] && cmd_d[READ_SLOT][CMD_RESET_N]); //cke and rst_n should stay high when reset sequence is already done
assert(cmd_d[WRITE_SLOT][CMD_CKE] && cmd_d[WRITE_SLOT][CMD_RESET_N]); //cke and rst_n should stay high when reset sequence is already done
end
end
if(state_calibrate == DONE_CALIBRATE) begin
assert(reset_done);
end
if(state_calibrate != DONE_CALIBRATE && !past_sync_rst_controller) begin
assert(o_wb_stall); //if not yet finished calibrating, stall should never go low
end
if(state_calibrate != DONE_CALIBRATE) begin
assert(f_empty); //if not yet finished calibrating, stall should never go low
end
if(!f_empty) begin
assert(state_calibrate == DONE_CALIBRATE);
end
if(train_delay == 0 && state_calibrate == FINISH_READ) begin//remove
assume(f_sum_of_pending_acks == 0);
end
end
//`ifdef UNDER_CONSTRUCTION
//make assertions on what is inside the fifo
always @* begin
if(!f_empty && !f_full) begin //make assertion when there is only 1 data on the pipe
if(stage1_pending) begin //request is still on stage1
assert(stage1_bank == f_read_data[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]); //bank must match
assert(stage1_col == {f_read_data[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}); //column address must match
assert(stage1_we == f_read_data[0]); //i_wb_we must be high
end
if(stage2_pending) begin //request is now on stage2
assert(stage2_bank == f_read_data[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]); //bank must match
assert(stage2_col == {f_read_data[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}); //column address must match
assert(stage2_we == f_read_data[0]); //i_wb_we must be high
end
end
if(f_full) begin //both stages have request
//stage2 is the request on the tip of the fifo
assert(stage2_bank == f_read_data[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]); //bank must match
assert(stage2_col == {f_read_data[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}); //column address must match
assert(stage2_we == f_read_data[0]); //i_wb_we must be high
//stage1 is the request on the other element of the fifo
//(since the fifo only has 2 elements, the other element that
//is not the tip will surely be the 2nd request that is being
//handles by stage1)
assert(stage1_bank == f_read_data_next[(COL_BITS - $clog2(serdes_ratio*2)) + 1 +: BA_BITS]); //bank must match
assert(stage1_col == {f_read_data_next[1 +: COL_BITS - $clog2(serdes_ratio*2)], 3'b000}); //column address must match
assert(stage1_we == f_read_data_next[0]); //i_wb_we must be high
end
end
//`endif
always @* begin
assert(f_bank_status == bank_status_q);
end
(*keep*) reg[31:0] bank;
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
//reset bank status and active row
for(f_index_1=0; f_index_1 < (1<<BA_BITS); f_index_1=f_index_1+1) begin
f_bank_status[f_index_1] <= 0;
f_bank_status_2[f_index_1] = 0;
f_bank_active_row[f_index_1] <= 0;
end
end
else begin
//check if a DDR3 command is issued
if(cmd_d[PRECHARGE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0010) begin //PRECHARGE
bank = cmd_d[PRECHARGE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1];
if(cmd_d[PRECHARGE_SLOT][10]) begin //A10 precharge all banks
for(f_index_1=0; f_index_1 < (1<<BA_BITS); f_index_1=f_index_1+1) begin
f_bank_status_2[f_index_1] = 0;
end
end
else begin
//f_bank_status <= f_bank_status & ~(1<<bank); //set to zero to idle bank
//f_bank_status[bank] <= 0; //set to zero to idle bank
f_bank_status_2 = f_bank_status_2 & ~(1<<bank); //set to zero to idle bank
end
assert(bank <= 7);
end
if(cmd_d[ACTIVATE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0011) begin //ACTIVATE
bank = cmd_d[ACTIVATE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1];
// f_bank_status <= f_bank_status | (1<<bank); //bank will be turned active
//f_bank_status[bank] <= 1;
assert(bank <= 7);
f_bank_status_2 = f_bank_status_2 | (1<<bank); //bank will be turned active
f_bank_active_row[bank] <= cmd_d[ACTIVATE_SLOT][CMD_ADDRESS_START:0]; //save row to be activated
end
f_bank_status <= f_bank_status_2;
end
end
assign f_write_slot = WRITE_SLOT;
assign f_read_slot = READ_SLOT;
assign f_precharge_slot = PRECHARGE_SLOT;
assign f_activate_slot = ACTIVATE_SLOT;
always @(posedge i_controller_clk) begin
if(!f_empty) begin//there is an ongoing wb request
assert(stage1_pending || stage2_pending);
end
if((stage1_pending || stage2_pending) && state_calibrate == DONE_CALIBRATE && i_wb_cyc) begin
assert(!f_empty || f_write_fifo);
end
end
always @(posedge i_controller_clk) begin
if(f_past_valid) begin
if(instruction_address != 22 && $past(instruction_address) != 22) begin
assert(!f_write_fifo); //must have no new request when not inside tREFI
end
if(instruction_address != 22 && $past(instruction_address) != 22) begin
assert(o_wb_stall);
assert(o_wb_stall_calib);
end
//delay_counter is zero at first clock of new instruction address, the actual delay_clock wil start at next clock cycle
if(instruction_address == 19 && delay_counter != 0) begin
assert(o_wb_stall);
assert(o_wb_stall_calib);
end
if(instruction_address == 20 || instruction_address == 21) begin //no pending request at precharge all and refresh command
assert(!stage1_pending);
assert(!stage2_pending);
end
if($past(o_wb_stall_q) && stage1_pending) begin //if pipe did not move forward
assert(stage1_we == $past(stage1_we));
assert(stage1_aux == $past(stage1_aux));
assert(stage1_bank == $past(stage1_bank));
assert(stage1_col == $past(stage1_col));
assert(stage1_row == $past(stage1_row));
assert(stage1_dm == $past(stage1_dm));
end
end
end
always @* begin
if(instruction_address != 22 && instruction_address != 19) begin
assert(!stage1_pending && !stage2_pending); //must be pending except in tREFI and in prestall delay
end
if(!reset_done) begin
assert(stage1_pending == 0 && stage2_pending == 0);
end
if(state_calibrate <= ISSUE_READ) begin
for(f_index_1 = 0; f_index_1 < 1; f_index_1 = f_index_1 + 1) begin
assert(o_wb_ack_read_q[f_index_1] == 0);
end
for(f_index_1 = 0; f_index_1 < READ_ACK_PIPE_WIDTH; f_index_1 = f_index_1 + 1) begin
assert(shift_reg_read_pipe_q[f_index_1] == 0);
end
end
if( state_calibrate < ISSUE_WRITE_1 ) begin
assert(bank_status_q == 0);
end
if(state_calibrate != DONE_CALIBRATE) begin
assert(o_wb_ack == 0); //o_wb_ack must not go high before done calibration
end
if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= ANALYZE_DATA) begin
if(stage1_pending) begin
assert(!stage1_we == stage1_aux); //if write, then aux id must be 1 else 0
end
if(stage2_pending) begin
assert(!stage2_we == stage2_aux); //if write, then aux id must be 1 else 0
end
end
assert(state_calibrate <= DONE_CALIBRATE);
end
wire[3:0] f_nreqs, f_nacks, f_outstanding, f_ackwait_count, f_stall_count;
wire[3:0] f_nreqs_2, f_nacks_2, f_outstanding_2;
reg[READ_ACK_PIPE_WIDTH+1:0] f_ack_pipe_after_stage2;
reg[AUX_WIDTH:0] f_aux_ack_pipe_after_stage2[READ_ACK_PIPE_WIDTH+1:0];
integer f_ack_pipe_marker;
integer f_sum_of_pending_acks = 0;
always @* begin
if(past_sync_rst_controller) begin
assume(f_nreqs == 0);
assume(f_nacks == 0);
end
if(state_calibrate != IDLE) assume(added_read_pipe_max == 1);
f_sum_of_pending_acks = stage1_pending + stage2_pending;
for(f_index_1 = 0; f_index_1 < READ_ACK_PIPE_WIDTH; f_index_1 = f_index_1 + 1) begin
f_sum_of_pending_acks = f_sum_of_pending_acks + shift_reg_read_pipe_q[f_index_1][0] + 0;
end
for(f_index_1 = 0; f_index_1 < 2; f_index_1 = f_index_1 + 1) begin //since added_read_pipe_max is assumed to be one, only the first two bits of o_wb_ack_read_q is relevant
f_sum_of_pending_acks = f_sum_of_pending_acks + o_wb_ack_read_q[f_index_1][0] + 0;
end
//the remaining o_wb_ack_read_q (>2) should stay zero at
//all instance
for(f_index_1 = 2; f_index_1 < MAX_ADDED_READ_ACK_DELAY ; f_index_1 = f_index_1 + 1) begin
assert(o_wb_ack_read_q[f_index_1] == 0);
end
f_aux_ack_pipe_after_stage2[READ_ACK_PIPE_WIDTH+1] = o_wb_ack_read_q[0]; //last stage of f_aux_ack_pipe_after_stage2 is also the last ack stage
f_aux_ack_pipe_after_stage2[READ_ACK_PIPE_WIDTH] = o_wb_ack_read_q[1];
for(f_index_1 = 0; f_index_1 < READ_ACK_PIPE_WIDTH; f_index_1 = f_index_1 + 1) begin
f_aux_ack_pipe_after_stage2[READ_ACK_PIPE_WIDTH - 1 - f_index_1] = shift_reg_read_pipe_q[f_index_1];
end
f_ack_pipe_after_stage2 = {
o_wb_ack_read_q[0][0],
o_wb_ack_read_q[1][0],
shift_reg_read_pipe_q[0][0],
shift_reg_read_pipe_q[1][0],
shift_reg_read_pipe_q[2][0],
shift_reg_read_pipe_q[3][0],
shift_reg_read_pipe_q[4][0]
};
if(f_ackwait_count > F_MAX_STALL) begin
assert(|f_ack_pipe_after_stage2[(READ_ACK_PIPE_WIDTH+1) : (f_ackwait_count - F_MAX_STALL - 1)]); //at least one stage must be high
end
if(!past_sync_rst_controller && state_calibrate == DONE_CALIBRATE) begin
assert(f_outstanding == f_sum_of_pending_acks || !i_wb_cyc);
end
else if(past_sync_rst_controller) begin
assert(f_sum_of_pending_acks == 0);
end
if(state_calibrate != DONE_CALIBRATE && !past_sync_rst_controller) begin
assert(f_outstanding == 0 || !i_wb_cyc);
end
if(state_calibrate <= ISSUE_WRITE_1 && !past_sync_rst_controller) begin
//not inside tREFI, prestall delay, nor precharge
assert(f_outstanding == 0 || !i_wb_cyc);
assert(f_sum_of_pending_acks == 0);
end
if(state_calibrate == READ_DATA && !past_sync_rst_controller) begin
assert(f_outstanding == 0 || !i_wb_cyc);
assert(f_sum_of_pending_acks <= 3);
if((f_sum_of_pending_acks > 1) && o_wb_ack_read_q[0]) begin
assert(o_wb_ack_read_q[0] == {0, 1'b1}); //if sum of pending acks > 1 then the first two will be write and have aux of 0, while the last will have aux of 1 (read)
end
f_ack_pipe_marker = 0;
for(f_index_1 = 0; f_index_1 < READ_ACK_PIPE_WIDTH + 2; f_index_1 = f_index_1 + 1) begin //check each ack stage starting from last stage
if(f_aux_ack_pipe_after_stage2[f_index_1][0]) begin //if ack is high
if(f_aux_ack_pipe_after_stage2[f_index_1][AUX_WIDTH:1] == 1) begin //ack for read
assert(f_ack_pipe_marker == 0); //read ack must be the last ack on the pipe(f_pipe_marker must still be zero)
f_ack_pipe_marker = f_ack_pipe_marker + 1;
assert(!stage1_pending && !stage2_pending); //a single read request must be the last request on this calibration
end
else begin //ack for write
assert(f_aux_ack_pipe_after_stage2[f_index_1][AUX_WIDTH:1] == 0);
f_ack_pipe_marker = f_ack_pipe_marker + 1;
end
end
end
assert(f_ack_pipe_marker <= 3);
end
if(state_calibrate == ANALYZE_DATA && !past_sync_rst_controller) begin
assert(f_outstanding == 0 || !i_wb_cyc);
assert(f_sum_of_pending_acks == 0);
end
if(state_calibrate != DONE_CALIBRATE && !past_sync_rst_controller) begin //if not yet done calibration, no request should be accepted
assert(f_nreqs == 0);
assert(f_nacks == 0);
assert(f_outstanding == 0 || !i_wb_cyc);
end
if(state_calibrate == ISSUE_WRITE_2 || state_calibrate == ISSUE_READ) begin
if(calib_stb == 1) begin
assert(calib_aux == 0);
assert(calib_we == 1);
end
end
if(state_calibrate == READ_DATA) begin
if(calib_stb == 1) begin
assert(calib_aux == 1);
assert(calib_we == 0);
end
end
if(state_calibrate <= ISSUE_WRITE_1 || state_calibrate == ANALYZE_DATA || state_calibrate == DONE_CALIBRATE) begin
assert(calib_stb == 0);
end
if(!stage1_pending) begin
assert(!stage1_stall);
end
if(!stage2_pending) begin
assert(!stage2_stall);
end
end
always @(posedge i_controller_clk) begin
if(f_past_valid) begin
if(instruction_address != 22 && instruction_address != 19 && $past(i_wb_cyc) && !past_sync_rst_controller) begin
assert(f_nreqs == $past(f_nreqs));
end
if(state_calibrate == DONE_CALIBRATE && $past(state_calibrate) != DONE_CALIBRATE && !past_sync_rst_controller) begin//just started DONE_CALBRATION
assert(f_nreqs == 0);
assert(f_nacks == 0);
assert(f_outstanding == 0);
assert(f_sum_of_pending_acks == 0);
end
if((!stage1_pending || !stage2_pending) && $past(state_calibrate) == DONE_CALIBRATE && state_calibrate == DONE_CALIBRATE
&& instruction_address == 22 && $past(instruction_address == 22)) begin
assert(!o_wb_stall);//if even 1 of the stage is empty, o_wb_stall must be low
end
end
end
//test the delay_before*
always @* begin
for(f_index_1=0; f_index_1< (1<<BA_BITS); f_index_1=f_index_1+1) begin
assert(delay_before_precharge_counter_q[f_index_1] <= max(ACTIVATE_TO_PRECHARGE_DELAY, max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY)));
assert(delay_before_activate_counter_q[f_index_1] <= PRECHARGE_TO_ACTIVATE_DELAY);
assert(delay_before_write_counter_q[f_index_1] <= (max(READ_TO_WRITE_DELAY,ACTIVATE_TO_WRITE_DELAY) + 1) );
assert(delay_before_read_counter_q[f_index_1] <= (max(WRITE_TO_READ_DELAY,ACTIVATE_TO_READ_DELAY)) + 1);
end
if(stage2_pending) begin
if(delay_before_precharge_counter_q[stage2_bank] == max(ACTIVATE_TO_PRECHARGE_DELAY, max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY))) begin
assert(f_stall_count == 0);
//assert(f_ackwait_count == 0);
end
if(delay_before_activate_counter_q[stage2_bank] == PRECHARGE_TO_ACTIVATE_DELAY && !bank_status_q[stage2_bank]) begin
assert(f_stall_count <= (max(ACTIVATE_TO_PRECHARGE_DELAY, max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY)) + 1));
//assert(f_ackwait_count <= (max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY) + 2));
end
//if there is still no pending ack
if(!(|f_ack_pipe_after_stage2)) begin
//At f_ackwait_count == F_MAX_STALL, the
//r/w command must be issued already (or stage2_update is high)
if(stage2_update) begin
assert(f_ackwait_count <= F_MAX_STALL);
end
if(delay_before_precharge_counter_q[stage2_bank] == max(ACTIVATE_TO_PRECHARGE_DELAY, max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY))) begin
assert(f_ackwait_count == 0);
end
if(delay_before_activate_counter_q[stage2_bank] == PRECHARGE_TO_ACTIVATE_DELAY && !bank_status_q[stage2_bank]) begin
assert(f_ackwait_count <= (max(ACTIVATE_TO_PRECHARGE_DELAY, max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY)) + 1));
end
/*
for(f_index_1 = 0; f_index_1 <= PRECHARGE_TO_ACTIVATE_DELAY; f_index_1= f_index_1 +1 ) begin
if(delay_before_activate_counter_q[stage2_bank] == PRECHARGE_TO_ACTIVATE_DELAY - f_index_1) begin
assert(f_ackwait_count <= (max(WRITE_TO_PRECHARGE_DELAY,READ_TO_PRECHARGE_DELAY) + 1 + f_index_1));
end
end
*/
end
end
end
// Test time parameter violations
reg[6:0] f_precharge_time_stamp[(1<<BA_BITS)-1:0];
reg[6:0] f_activate_time_stamp[(1<<BA_BITS)-1:0];
reg[6:0] f_read_time_stamp[(1<<BA_BITS)-1:0];
reg[6:0] f_write_time_stamp[(1<<BA_BITS)-1:0];
reg[6:0] f_timer = 0;
initial begin
for(f_index_1=0; f_index_1 < (1<<BA_BITS); f_index_1=f_index_1+1) begin
f_precharge_time_stamp[f_index_1] = 0;
f_activate_time_stamp[f_index_1] = 0;
f_read_time_stamp[f_index_1] = 0;
f_write_time_stamp[f_index_1] = 0;
end
end
(*anyconst*) reg[2:0] bank_const;
always @(posedge i_controller_clk) begin
f_timer <= f_timer + 4;
if(f_past_valid) begin
assume($past(f_timer) < f_timer); //assume that counter will never overflow
end
end
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
for(f_index_1=0; f_index_1 < (1<<BA_BITS); f_index_1=f_index_1+1) begin
f_precharge_time_stamp[f_index_1] <= 0;
f_activate_time_stamp[f_index_1] <= 0;
f_read_time_stamp[f_index_1] <= 0;
f_write_time_stamp[f_index_1] <= 0;
end
end
else begin
//check if a DDR3 command is issued
if(cmd_d[PRECHARGE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0010) begin //PRECHARGE
f_precharge_time_stamp[cmd_d[PRECHARGE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] <= f_timer + PRECHARGE_SLOT;
end
if(cmd_d[ACTIVATE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0011) begin //ACTIVATE
f_activate_time_stamp[cmd_d[ACTIVATE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] <= f_timer + ACTIVATE_SLOT;
end
if(cmd_d[WRITE_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0100) begin //WRITE
f_write_time_stamp[cmd_d[WRITE_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] <= f_timer + WRITE_SLOT;
//Check tCCD (write-to-write delay)
assert((f_timer+WRITE_SLOT) - f_write_time_stamp[bank_const] >= tCCD);
end
if(cmd_d[READ_SLOT][CMD_CS_N:CMD_WE_N] == 4'b0101) begin //READ
f_read_time_stamp[cmd_d[READ_SLOT][CMD_BANK_START:CMD_ADDRESS_START+1]] <= f_timer + READ_SLOT;
//Check tCCD (read-to-read delay)
assert((f_timer+READ_SLOT) - f_read_time_stamp[bank_const] >= tCCD);
end
end
end
always @* begin
// make sure saved time stamp is valid
assert(f_precharge_time_stamp[bank_const] <= f_timer);
assert(f_activate_time_stamp[bank_const] <= f_timer);
assert(f_read_time_stamp[bank_const] <= f_timer);
assert(f_write_time_stamp[bank_const] <= f_timer);
// Check tRTP (Internal READ Command to PRECHARGE Command delay in SAME BANK)
if(f_precharge_time_stamp[bank_const] > f_read_time_stamp[bank_const]) begin
assert((f_precharge_time_stamp[bank_const] - f_read_time_stamp[bank_const]) >= ps_to_nCK(tRTP));
end
// Check tWTR (Delay from start of internal write transaction to internal read command)
if(f_read_time_stamp[bank_const] > f_write_time_stamp[bank_const]) begin
assert((f_read_time_stamp[bank_const] - f_write_time_stamp[bank_const]) >= (CWL_nCK + 3'd4 + ps_to_nCK(tWTR)));
end
// Check tRCD (ACT to internal read delay time)
if(f_read_time_stamp[bank_const] > f_activate_time_stamp[bank_const]) begin
assert((f_read_time_stamp[bank_const] - f_activate_time_stamp[bank_const]) >= ps_to_nCK(tRCD));
end
// Check tRCD (ACT to internal write delay time)
if(f_write_time_stamp[bank_const] > f_activate_time_stamp[bank_const]) begin
assert((f_write_time_stamp[bank_const] - f_activate_time_stamp[bank_const]) >= ps_to_nCK(tRCD));
end
// Check tRP (PRE command period)
if(f_activate_time_stamp[bank_const] > f_precharge_time_stamp[bank_const]) begin
assert((f_activate_time_stamp[bank_const] - f_precharge_time_stamp[bank_const]) >= ps_to_nCK(tRP));
end
// Check tRAS (ACTIVE to PRECHARGE command period)
if(f_precharge_time_stamp[bank_const] > f_activate_time_stamp[bank_const]) begin
assert((f_precharge_time_stamp[bank_const] - f_activate_time_stamp[bank_const]) >= ps_to_nCK(tRAS));
end
// Check tWR (WRITE recovery time for write-to-precharge)
if(f_precharge_time_stamp[bank_const] > f_write_time_stamp[bank_const]) begin
assert((f_precharge_time_stamp[bank_const] - f_write_time_stamp[bank_const]) >= (CWL_nCK + 3'd4 + ps_to_nCK(tWR)));
end
// Check delay from read-to-write
if(f_write_time_stamp[bank_const] > f_read_time_stamp[bank_const]) begin
assert((f_write_time_stamp[bank_const] - f_read_time_stamp[bank_const]) >= (CL_nCK + tCCD + 3'd2 - CWL_nCK));
end
end
// extra assertions to make sure engine starts properly
always @* begin
//if(!past_sync_rst_controller) begin
assert(instruction_address <= 22);
assert(state_calibrate <= DONE_CALIBRATE);
if(!o_wb_stall) begin
assert(state_calibrate == DONE_CALIBRATE);
assert(instruction_address == 22 || (instruction_address == 19 && delay_counter == 0));
end
if(instruction_address == 19 && delay_counter != 0 && state_calibrate == DONE_CALIBRATE) begin
if(stage1_pending || stage2_pending) begin
assert(pause_counter);
end
end
if(stage1_pending || stage2_pending) begin
assert(state_calibrate > ISSUE_WRITE_1);
assert(instruction_address == 22 || instruction_address == 19);
end
if(instruction_address < 13) begin
assert(state_calibrate == IDLE);
end
if(state_calibrate > IDLE && state_calibrate <= BITSLIP_DQS_TRAIN_2) begin
assert(instruction_address == 13);
assert(pause_counter);
end
if(state_calibrate > START_WRITE_LEVEL && state_calibrate <= WAIT_FOR_FEEDBACK) begin
assert(instruction_address == 17);
assert(pause_counter);
end
if(pause_counter) begin
assert(delay_counter != 0);
end
if(state_calibrate > ISSUE_WRITE_1 && state_calibrate <= ANALYZE_DATA) begin
assume(instruction_address == 22); //write-then-read calibration will not take more than tREFI (7.8us, delay a address 22)
assert(reset_done);
end
if(state_calibrate == DONE_CALIBRATE) begin
assert(reset_done);
assert(instruction_address >= 19);
end
if(reset_done) begin
assert(instruction_address >= 19);
end
if(!reset_done) begin
assert(!stage1_pending && !stage2_pending);
assert(o_wb_stall);
assert(o_wb_stall_calib);
end
if(reset_done) begin
assert(instruction_address >= 19 && instruction_address <= 22);
end
//delay_counter is zero at first clock of new instruction address, the actual delay_clock wil start at next clock cycle
if(instruction_address == 19 && delay_counter != 0) begin
assert(o_wb_stall);
assert(o_wb_stall_calib);
end
if(instruction_address == 19 && pause_counter) begin //pre-stall delay to finish all remaining requests
assert(delay_counter == PRE_REFRESH_DELAY);
//assert(reset_done);
//assert(state_calibrate >= ISSUE_WRITE_1);
end
//end
end
/*
// verify the wishbone 2
localparam F_TEST_WB2_DATA_WIDTH = wb2_sel_bits + 5 + lanes_clog2 + 4 + 1; //WB2_SEL + CNTVALUEIN + LANE_NUMBER + MEMORY_MAPPED_ADDRESS + REQUEST_TYPE
reg f_read_fifo_2, f_write_fifo_2;
wire f_empty_2, f_full_2;
reg[F_TEST_WB2_DATA_WIDTH - 1:0] f_write_data_2 = 0;
reg[F_TEST_WB2_DATA_WIDTH - 1:0] f_read_data_2, f_read_data_2_q;
reg f_o_wb2_ack_q = 0; //registered o_wb2_ack
(*keep*) reg[LANES-1:0] f_delay_ld = 0;
//accept request
always @* begin
if(f_empty_2 && (i_wb2_cyc && SECOND_WISHBONE)) begin
assert(!wb2_stb && !o_wb2_ack);
end
if(!wb2_stb && !o_wb2_ack) begin
assert(f_empty_2);
end
f_write_data_2 = 0;
f_write_fifo_2 = 0;
if(i_wb2_stb && !o_wb2_stall && (i_wb2_cyc && SECOND_WISHBONE)) begin //if there is request
if(i_wb2_we) begin //write request
f_write_data_2 = {i_wb2_sel, i_wb2_data[4:0], i_wb2_data[5 +: lanes_clog2], i_wb2_addr[3:0], i_wb2_we}; //CNTVALUEIN + LANE_NUMBER + MEMORY_MAPPED_ADDRESS + REQUEST_TYPE
assume(i_wb2_data[5 +: lanes_clog2] < LANES);
end
else begin //read request
f_write_data_2 = {i_wb2_addr[4 +: lanes_clog2], i_wb2_addr[3:0], i_wb2_we}; //LANE_NUMBER + MEMORY_MAPPED_ADDRESS + REQUEST_TYPE
assume(i_wb2_addr[4 +: lanes_clog2] < LANES);
end
f_write_fifo_2 = 1;
end
if(state_calibrate != DONE_CALIBRATE && i_wb2_stb) begin
// must not be a read/write to delays when not yet done calibrating
assume(i_wb2_addr[3:0] > 3);
end
end
//verify outcome of request
always @(posedge i_controller_clk) begin
if(sync_rst_controller) begin
f_o_wb2_ack_q <= 0;
f_read_data_2_q <= 0;
end
else begin
f_o_wb2_ack_q <= o_wb2_ack && f_read_data_2[0] && (i_wb2_cyc && SECOND_WISHBONE);
f_read_data_2_q <= f_read_data_2;
end
end
always @* begin
if(!past_sync_rst_controller) begin
if(wb2_stb && o_wb2_ack) begin
assert(f_full_2 || !(i_wb2_cyc && SECOND_WISHBONE));
end
if(f_full_2) begin
assert(wb2_stb && o_wb2_ack);
assert(f_outstanding_2 == 2 || !(i_wb2_cyc && SECOND_WISHBONE));
end
if(f_outstanding_2 == 2) begin
assert(f_full_2 || !(i_wb2_cyc && SECOND_WISHBONE));
end
if(f_empty_2) begin
assert(f_outstanding_2 == 0 || !(i_wb2_cyc && SECOND_WISHBONE));
end
if(f_outstanding_2 == 0) begin
assert(f_empty_2 || !(i_wb2_cyc && SECOND_WISHBONE));
end
end
assert(f_outstanding_2 <= 2);
f_read_fifo_2 = 0;
if(o_wb2_ack && !f_read_data_2[0] && !past_sync_rst_controller) begin //read request
f_read_fifo_2 = 1;
end
if(o_wb2_ack && f_read_data_2[0] && !past_sync_rst_controller) begin
f_read_fifo_2 = 1;
end
end
//check request action at wb_ack
always @(posedge i_controller_clk) begin
if(f_past_valid) begin
assert(!o_wb2_stall || !i_rst_n || !$past(i_rst_n)); //never stall
//write request
if(f_o_wb2_ack_q && i_rst_n && (&f_read_data_2_q[5 + lanes_clog2 + 4 + 1 +: $rtoi($ceil( (lanes_clog2 + 5)/8.0 ))])) begin //the sel bits must be high
case(f_read_data_2_q[4:1]) //memory-mapped address
0: begin
assert(o_phy_odelay_data_ld == (1 << f_read_data_2_q[5 +: lanes_clog2])); //the phy lane to be loaded must be high
assert(o_phy_odelay_data_cntvaluein == f_read_data_2_q[(5 + lanes_clog2) +: 5]); //the phy interface for cntvalue must already be updated
assert($past(wb2_update));
end
1: begin
assert(o_phy_odelay_dqs_ld == (1 << f_read_data_2_q[5 +: lanes_clog2])); //the phy lane to be loaded must be high
assert(o_phy_odelay_dqs_cntvaluein == f_read_data_2_q[(5 + lanes_clog2) +: 5]); //the phy interface for cntvalue must already be updated
assert($past(wb2_update));
end
2: begin
assert(o_phy_idelay_data_ld == (1 << f_read_data_2_q[5 +: lanes_clog2])); //the phy lane to be loaded must be high
assert(o_phy_idelay_data_cntvaluein == f_read_data_2_q[(5 + lanes_clog2) +: 5]); //the phy interface for cntvalue must already be updated
assert($past(wb2_update));
end
3: begin
assert(o_phy_idelay_dqs_ld == (1 << f_read_data_2_q[5 +: lanes_clog2])); //the phy lane to be loaded must be high
assert(o_phy_idelay_dqs_cntvaluein == f_read_data_2_q[(5 + lanes_clog2) +: 5]); //the phy interface for cntvalue must already be updated
assert($past(wb2_update));
end
endcase
end
else if(i_rst_n) begin
assert(!$past(wb2_update) || !$past((i_wb2_cyc && SECOND_WISHBONE)));
end
//read request
if(o_wb2_ack && !f_read_data_2[0] && i_rst_n && (i_wb2_cyc && SECOND_WISHBONE) && !(f_o_wb2_ack_q && f_read_data_2_q[1 +: (4 + lanes_clog2)] == f_read_data_2[1 +: (4 + lanes_clog2)] )) begin
case(f_read_data_2[4:1]) //memory-mapped address
0: begin
assert(o_wb2_data == odelay_data_cntvaluein[f_read_data_2[5 +: lanes_clog2]]); //the stored delay must match the wb2 output
end
1: begin
assert(o_wb2_data == odelay_dqs_cntvaluein[f_read_data_2[5 +: lanes_clog2]]); //the stored delay must match the wb2 output
end
2: begin
assert(o_wb2_data == idelay_data_cntvaluein[f_read_data_2[5 +: lanes_clog2]]); //the stored delay must match the wb2 output
end
3: begin
assert(o_wb2_data == idelay_dqs_cntvaluein[f_read_data_2[5 +: lanes_clog2]]); //the stored delay must match the wb2 output
end
4: begin
assert(o_wb2_data[0] == $past(i_phy_idelayctrl_rdy));
assert(o_wb2_data[5:1] == $past(state_calibrate));
assert(o_wb2_data[10:6] == $past(instruction_address));
assert(o_wb2_data[14:11] == $past(added_read_pipe_max));
end
5: begin
for(f_index_1 = 0; f_index_1 < LANES; f_index_1 = f_index_1 + 1) begin
assert(o_wb2_data[4*f_index_1 +: 4] == $past(added_read_pipe[f_index_1]));
end
end
6: begin
assert(o_wb2_data == $past(dqs_store[31:0]));
end
7: begin
for(f_index_1 = 0; 8*f_index_1 < 32 && f_index_1 < LANES; f_index_1 = f_index_1 + 1) begin
assert(o_wb2_data[8*f_index_1 +: 8] == $past(i_phy_iserdes_bitslip_reference[8*f_index_1 +: 8]));
end
end
8: begin
assert(o_wb2_data == $past(read_data_store[31:0]));
end
9: begin
assert(o_wb2_data == $past(write_pattern[31:0]));
end
endcase
end
end
end
wire[2:0] f_read_data_2_lane;
assign f_read_data_2_lane = f_read_data_2[5 +: lanes_clog2];
always @(posedge i_controller_clk) begin
if(f_past_valid) begin
for(f_index_1 = 0; f_index_1 < LANES; f_index_1 = f_index_1 + 1) begin
if(o_phy_bitslip[f_index_1]) begin
//Bitslip cannot be asserted for two consecutive CLKDIV cycles; Bitslip must be
//deasserted for at least one CLKDIV cycle between two Bitslip assertions.
assert(!$past(o_phy_bitslip[f_index_1]));
end
end
end
end
mini_fifo #(
.FIFO_WIDTH(1), //the fifo will have 2**FIFO_WIDTH positions
.DATA_WIDTH(F_TEST_WB2_DATA_WIDTH) //each FIFO position can store DATA_WIDTH bits
) fifo_2 (
.i_clk(i_controller_clk),
.i_rst_n(i_rst_n && (i_wb2_cyc && SECOND_WISHBONE)), //reset outstanding request at reset or when cyc goes low
.read_fifo(f_read_fifo_2),
.write_fifo(f_write_fifo_2),
.empty(f_empty_2),
.full(f_full_2),
.write_data(f_write_data_2),
.read_data(f_read_data_2)
);
*/
//assumption on when to do request (so as not to violate the
//F_MAX_STALL property of fwb_slave)
always @* begin
if(!(state_calibrate == DONE_CALIBRATE && instruction_address == 22)) begin //if in initialization/refresh sequence, no request should come in to the controller wishbone
assume(!i_wb_stb);
end
end
fwb_slave #(
// {{{
.AW(wb_addr_bits),
.DW(wb_data_bits),
.F_MAX_STALL(F_MAX_STALL),
.F_MAX_ACK_DELAY(F_MAX_ACK_DELAY),
.F_LGDEPTH(4),
.F_MAX_REQUESTS(10),
// OPT_BUS_ABORT: If true, the master can drop CYC at any time
// and must drop CYC following any bus error
.OPT_BUS_ABORT(1),
//
// If true, allow the bus to be kept open when there are no
// outstanding requests. This is useful for any master that
// might execute a read modify write cycle, such as an atomic
// add.
.F_OPT_RMW_BUS_OPTION(1),
//
//
// If true, allow the bus to issue multiple discontinuous
// requests.
// Unlike F_OPT_RMW_BUS_OPTION, these requests may be issued
// while other requests are outstanding
.F_OPT_DISCONTINUOUS(1),
//
//
// If true, insist that there be a minimum of a single clock
// delay between request and response. This defaults to off
// since the wishbone specification specifically doesn't
// require this. However, some interfaces do, so we allow it
// as an option here.
.F_OPT_MINCLOCK_DELAY(1),
// }}}
) wb_properties (
// {{{
.i_clk(i_controller_clk),
.i_reset(past_sync_rst_controller),
// The Wishbone bus
.i_wb_cyc(i_wb_cyc),
.i_wb_stb(i_wb_stb),
.i_wb_we(i_wb_we),
.i_wb_addr(i_wb_addr),
.i_wb_data(i_wb_data),
.i_wb_sel(i_wb_sel),
//
.i_wb_ack(o_wb_ack),
.i_wb_stall(o_wb_stall),
.i_wb_idata(o_wb_data),
.i_wb_err(1'b0),
// Some convenience output parameters
.f_nreqs(f_nreqs),
.f_nacks(f_nacks),
.f_outstanding(f_outstanding),
.f_ackwait_count(f_ackwait_count),
.f_stall_count(f_stall_count)
// }}}
// }}}
);
/*
fwb_slave #(
// {{{
.AW(WB2_ADDR_BITS),
.DW(WB2_DATA_BITS),
.F_MAX_STALL(2),
.F_MAX_ACK_DELAY(2),
.F_LGDEPTH(4),
.F_MAX_REQUESTS(10),
// OPT_BUS_ABORT: If true, the master can drop CYC at any time
// and must drop CYC following any bus error
.OPT_BUS_ABORT(1),
//
// If true, allow the bus to be kept open when there are no
// outstanding requests. This is useful for any master that
// might execute a read modify write cycle, such as an atomic
// add.
.F_OPT_RMW_BUS_OPTION(1),
//
//
// If true, allow the bus to issue multiple discontinuous
// requests.
// Unlike F_OPT_RMW_BUS_OPTION, these requests may be issued
// while other requests are outstanding
.F_OPT_DISCONTINUOUS(1),
//
//
// If true, insist that there be a minimum of a single clock
// delay between request and response. This defaults to off
// since the wishbone specification specifically doesn't
// require this. However, some interfaces do, so we allow it
// as an option here.
.F_OPT_MINCLOCK_DELAY(1),
// }}}
) wb2_properties (
// {{{
.i_clk(i_controller_clk),
.i_reset(!i_rst_n),
// The Wishbone bus
.i_wb_cyc((i_wb2_cyc && SECOND_WISHBONE)),
.i_wb_stb(i_wb2_stb),
.i_wb_we(i_wb2_we),
.i_wb_addr(i_wb2_addr),
.i_wb_data(i_wb2_data),
.i_wb_sel(i_wb2_sel),
//
.i_wb_ack(o_wb2_ack),
.i_wb_stall(o_wb2_stall),
.i_wb_idata(o_wb2_data),
.i_wb_err(1'b0),
// Some convenience output parameters
.f_nreqs(f_nreqs_2),
.f_nacks(f_nacks_2),
.f_outstanding(f_outstanding_2),
// }}}
// }}}
);*/
`endif //endif for TEST_CONTROLLER_PIPELINE
`endif //endif for FORMAL
endmodule
`ifdef FORMAL
//FiFO with only 2 elements for verifying the contents of the controller
//2-stage pipeline
module mini_fifo #(
parameter FIFO_WIDTH = 1, //the fifo will have 2**FIFO_WIDTH positions
parameter DATA_WIDTH = 8 //each FIFO position can store DATA_WIDTH bits
)(
input wire i_clk, i_rst_n,
input wire read_fifo, write_fifo,
output reg empty, full,
input wire[DATA_WIDTH - 1:0] write_data,
output wire[DATA_WIDTH - 1:0] read_data,
output wire[DATA_WIDTH - 1:0] read_data_next
);
reg[FIFO_WIDTH-1:0] write_pointer=0, read_pointer=0;
reg[DATA_WIDTH - 1:0] fifo_reg[2**FIFO_WIDTH-1:0];
initial begin
empty = 1;
full = 0;
end
always @(posedge i_clk, negedge i_rst_n) begin
if(!i_rst_n) begin
empty <= 1;
full <=0;
read_pointer <= 0;
write_pointer <= 0;
end
else begin
if(read_fifo) begin
`ifdef FORMAL
assert(!empty);
`endif
if(!write_fifo) full <= 0;
//advance read pointer
read_pointer <= read_pointer + 1;
if(read_pointer + 1'b1 == write_pointer && !write_fifo) empty <= 1;
end
if(write_fifo) begin
`ifdef FORMAL
if(!read_fifo) assert(!full);
`endif
if(!read_fifo) empty <= 0;
//write to FiFo
fifo_reg[write_pointer] <= write_data;
//advance read pointer
write_pointer <= write_pointer + 1;
if(write_pointer + 1'b1 == read_pointer && !read_fifo) full <= 1'b1; //fifo should never be full
end
end
end
assign read_data = fifo_reg[read_pointer];
assign read_data_next = fifo_reg[!read_pointer]; //data after current pointer
`ifdef FORMAL
//mini-FiFo assertions
always @* begin
if(empty || full) begin
assert(write_pointer == read_pointer);
end
if(write_pointer == read_pointer) begin
assert(empty || full);
end
assert(!(empty && full));
//TASK ADD MORE ASSERTIONS
end
`endif
endmodule
`endif
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