248 lines
11 KiB
Verilog
248 lines
11 KiB
Verilog
////////////////////////////////////////////////////////////////////////////////
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//
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// Filename: ax7103_ddr3.v
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// Project: UberDDR3 - An Open Source DDR3 Controller
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//
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// Purpose: Example demo of UberDDR3 for ALINX AX7103 (xc7a100tfgg484-2). Mechanism:
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// - four LEDs will light up once UberDDR3 is done calibrating
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// - if UART (9600 Baud Rate)receives small letter ASCII (a-z), this value will be written to DDR3
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// - if UART receives capital letter ASCII (A-Z), the small letter equivalent will be retrieved from DDR3 by doing
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// - a read request, once read data is available this will be sent to UART to be streamed out.
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// THUS:
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// - Sendng "abcdefg" to the UART terminal will store that small latter to DDR3
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// - Then sending "ABCDEFG" to the UART terminal will return the small letter equivalent: "abcdefg"
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//
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// Engineer: Angelo C. Jacobo
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//
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////////////////////////////////////////////////////////////////////////////////
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//
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// Copyright (C) 2023-2025 Angelo Jacobo
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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//
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////////////////////////////////////////////////////////////////////////////////
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`timescale 1ns / 1ps
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module ax7103_ddr3
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(
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input wire sys_clk_p, // system clock positive on board
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input wire sys_clk_n, //system clock negative on board
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input wire i_rst_n,
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// DDR3 I/O Interface
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output wire ddr3_ck_p, ddr3_ck_n,
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output wire ddr3_reset_n,
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output wire ddr3_cke,
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output wire ddr3_cs_n,
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output wire ddr3_ras_n,
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output wire ddr3_cas_n,
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output wire ddr3_we_n,
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output wire[15-1:0] ddr3_addr,
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output wire[3-1:0] ddr3_ba,
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inout wire[32-1:0] ddr3_dq,
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inout wire[4-1:0] ddr3_dqs_p, ddr3_dqs_n,
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output wire[4-1:0] ddr3_dm,
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output wire ddr3_odt,
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// UART line
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input wire rx,
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output wire tx,
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//Debug LEDs
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output wire[3:0] led
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);
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wire sys_clk_200MHz;
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IBUFDS sys_clk_ibufgds
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(
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.O(sys_clk_200MHz),
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.I(sys_clk_p),
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.IB(sys_clk_n)
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);
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wire i_controller_clk, i_ddr3_clk, i_ref_clk, i_ddr3_clk_90;
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wire m_axis_tvalid;
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wire rx_empty;
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wire tx_full;
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wire o_wb_ack;
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wire[7:0] o_wb_data;
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wire o_aux;
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wire[7:0] rd_data;
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wire o_wb_stall;
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reg i_wb_stb = 0, i_wb_we;
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wire[63:0] o_debug1;
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reg[7:0] i_wb_data;
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reg[7:0] i_wb_addr;
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// o_debug1 taps on value of state_calibrate (can be traced inside ddr3_controller module)
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assign led[0] = !(o_debug1[4:0] != 23); //light up if not at DONE_CALIBRATE
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assign led[1] = !(o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
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assign led[2] = !(o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
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assign led[3] = !(o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
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always @(posedge i_controller_clk) begin
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begin
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i_wb_stb <= 0;
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i_wb_we <= 0;
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i_wb_addr <= 0;
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i_wb_data <= 0;
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if(!o_wb_stall && m_axis_tvalid) begin
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if(rd_data >= 97 && rd_data <= 122) begin //write to DDR3 if ASCII is small letter
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i_wb_stb <= 1;
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i_wb_we <= 1;
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i_wb_addr <= ~rd_data ;
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i_wb_data <= rd_data;
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end
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else if(rd_data >= 65 && rd_data <= 90) begin //read from DDR3 if ASCII is capital letter
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i_wb_stb <= 1; //make request
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i_wb_we <= 0; //read
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i_wb_addr <= ~(rd_data + 8'd32);
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end
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end
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end
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end
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wire clk_locked;
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clk_wiz clk_wiz_inst
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(
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// Clock out ports
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.clk_out1(i_controller_clk), //83.333 Mhz
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.clk_out2(i_ddr3_clk), // 333.333 MHz
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.clk_out3(i_ref_clk), // 200 MHz
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.clk_out4(i_ddr3_clk_90), // 333.333 MHz 90-degree
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// Status and control signals
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.reset(!i_rst_n),
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.locked(clk_locked),
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// Clock in ports
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.clk_in1(sys_clk_200MHz)
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);
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// UART TX/RXmodule from https://github.com/ben-marshall/uart
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uart_tx #(
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.BIT_RATE(9600),
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.CLK_HZ(83_333_333),
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.PAYLOAD_BITS(8),
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.STOP_BITS(1)
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) uart_tx_inst (
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.clk(i_controller_clk), // Top level system clock input.
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.resetn(i_rst_n && clk_locked && o_debug1[4:0] == 23), // Asynchronous active low reset.
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.uart_txd(tx), // UART transmit pin.
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.uart_tx_busy(), // Module busy sending previous item.
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.uart_tx_en(o_wb_ack), // Send the data on uart_tx_data
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.uart_tx_data(o_wb_data) // The data to be sent
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);
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uart_rx #(
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.BIT_RATE(9600),
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.CLK_HZ(83_333_333),
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.PAYLOAD_BITS(8),
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.STOP_BITS(1)
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) uart_rx_inst (
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.clk(i_controller_clk), // Top level system clock input.
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.resetn(i_rst_n && clk_locked && o_debug1[4:0] == 23), // Asynchronous active low reset.
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.uart_rxd(rx), // UART Recieve pin.
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.uart_rx_en(o_debug1[4:0] == 23), // Recieve enable
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.uart_rx_break(), // Did we get a BREAK message?
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.uart_rx_valid(m_axis_tvalid), // Valid data recieved/available.
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.uart_rx_data(rd_data) // The recieved data.
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);
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// UART module from https://github.com/alexforencich/verilog-uart (DOES NOT WORK ON OPENXC7, UberDDR3 cannot finish calibration when this UART is used)
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// uart #(.DATA_WIDTH(8)) uart_m
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// (
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// .clk(i_controller_clk),
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// .rst(!i_rst_n),
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// .s_axis_tdata(o_wb_data),
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// .s_axis_tvalid(o_wb_ack),
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// .s_axis_tready(),
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// .m_axis_tdata(rd_data),
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// .m_axis_tvalid(m_axis_tvalid),
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// .m_axis_tready(1),
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// .rxd(rx),
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// .txd(tx),
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// .prescale(1085) //9600 Baud Rate (83.33MHz/(8*9600))
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// );
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// DDR3 Controller
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ddr3_top #(
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.CONTROLLER_CLK_PERIOD(12_000), //ps, clock period of the controller interface
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.DDR3_CLK_PERIOD(3_000), //ps, clock period of the DDR3 RAM device (must be 1/4 of the CONTROLLER_CLK_PERIOD)
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.ROW_BITS(15), //width of row address
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.COL_BITS(10), //width of column address
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.BA_BITS(3), //width of bank address
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.BYTE_LANES(4), //number of DDR3 modules to be controlled
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.AUX_WIDTH(16), //width of aux line (must be >= 4)
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.WB2_ADDR_BITS(32), //width of 2nd wishbone address bus
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.WB2_DATA_BITS(32), //width of 2nd wishbone data bus
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.MICRON_SIM(0), //enable faster simulation for micron ddr3 model (shorten POWER_ON_RESET_HIGH and INITIAL_CKE_LOW)
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.ODELAY_SUPPORTED(0), //set to 1 when ODELAYE2 is supported
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.SECOND_WISHBONE(0), //set to 1 if 2nd wishbone is needed
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.ECC_ENABLE(0), // set to 1 or 2 to add ECC (1 = Side-band ECC per burst, 2 = Side-band ECC per 8 bursts , 3 = Inline ECC )
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.WB_ERROR(0), // set to 1 to support Wishbone error (asserts at ECC double bit error)
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.DIC(2'b01), //Output Driver Impedance Control (2'b00 = RZQ/6, 2'b01 = RZQ/7, RZQ = 240ohms) (only change when you know what you are doing)
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.RTT_NOM(3'b001) //RTT Nominal (3'b000 = disabled, 3'b001 = RZQ/4, 3'b010 = RZQ/2 , 3'b011 = RZQ/6, RZQ = 240ohms) (only change when you know what you
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) ddr3_top
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(
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//clock and reset
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.i_controller_clk(i_controller_clk),
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.i_ddr3_clk(i_ddr3_clk), //i_controller_clk has period of CONTROLLER_CLK_PERIOD, i_ddr3_clk has period of DDR3_CLK_PERIOD
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.i_ref_clk(i_ref_clk),
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.i_ddr3_clk_90(i_ddr3_clk_90),
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.i_rst_n(i_rst_n && clk_locked),
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// Wishbone inputs
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.i_wb_cyc(1), //bus cycle active (1 = normal operation, 0 = all ongoing transaction are to be cancelled)
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.i_wb_stb(i_wb_stb), //request a transfer
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.i_wb_we(i_wb_we), //write-enable (1 = write, 0 = read)
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.i_wb_addr(i_wb_addr), //burst-addressable {row,bank,col}
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.i_wb_data(i_wb_data), //write data, for a 4:1 controller data width is 8 times the number of pins on the device
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.i_wb_sel(16'hffff), //byte strobe for write (1 = write the byte)
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.i_aux(i_wb_we), //for AXI-interface compatibility (given upon strobe)
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// Wishbone outputs
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.o_wb_stall(o_wb_stall), //1 = busy, cannot accept requests
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.o_wb_ack(o_wb_ack), //1 = read/write request has completed
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.o_wb_data(o_wb_data), //read data, for a 4:1 controller data width is 8 times the number of pins on the device
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.o_aux(o_aux),
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// Wishbone 2 (PHY) inputs
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.i_wb2_cyc(), //bus cycle active (1 = normal operation, 0 = all ongoing transaction are to be cancelled)
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.i_wb2_stb(), //request a transfer
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.i_wb2_we(), //write-enable (1 = write, 0 = read)
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.i_wb2_addr(), //burst-addressable {row,bank,col}
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.i_wb2_data(), //write data, for a 4:1 controller data width is 8 times the number of pins on the device
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.i_wb2_sel(), //byte strobe for write (1 = write the byte)
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// Wishbone 2 (Controller) outputs
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.o_wb2_stall(), //1 = busy, cannot accept requests
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.o_wb2_ack(), //1 = read/write request has completed
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.o_wb2_data(), //read data, for a 4:1 controller data width is 8 times the number of pins on the device
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// PHY Interface (to be added later)
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// DDR3 I/O Interface
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.o_ddr3_clk_p(ddr3_ck_p),
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.o_ddr3_clk_n(ddr3_ck_n),
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.o_ddr3_reset_n(ddr3_reset_n),
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.o_ddr3_cke(ddr3_cke), // CKE
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.o_ddr3_cs_n(ddr3_cs_n), // chip select signal (controls rank 1 only)
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.o_ddr3_ras_n(ddr3_ras_n), // RAS#
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.o_ddr3_cas_n(ddr3_cas_n), // CAS#
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.o_ddr3_we_n(ddr3_we_n), // WE#
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.o_ddr3_addr(ddr3_addr),
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.o_ddr3_ba_addr(ddr3_ba),
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.io_ddr3_dq(ddr3_dq),
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.io_ddr3_dqs(ddr3_dqs_p),
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.io_ddr3_dqs_n(ddr3_dqs_n),
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.o_ddr3_dm(ddr3_dm),
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.o_ddr3_odt(ddr3_odt), // on-die termination
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.o_debug1(o_debug1),
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.o_debug2(),
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.o_debug3()
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);
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endmodule
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