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UberDDR3
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add more comments how design works

This commit is contained in:
AngeloJacobo 2024-05-05 16:00:09 +08:00
parent e4716b6675
commit 0fbd2e7cbb
1 changed files with 13 additions and 7 deletions
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20
arty_s7/arty_ddr3.v
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@ -38,12 +38,19 @@
wire[63:0] o_debug1; wire[63:0] o_debug1;
reg[7:0] i_wb_data; reg[7:0] i_wb_data;
reg[7:0] i_wb_addr; reg[7:0] i_wb_addr;
// o_debug1 taps on value of state_calibrate (can be traced inside ddr3_controller module)
assign led[0] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE assign led[0] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
assign led[1] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE assign led[1] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
assign led[2] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE assign led[2] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
assign led[3] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE assign led[3] = (o_debug1[4:0] == 23); //light up if at DONE_CALIBRATE
// what this design do is very simple:
// if UART receives small letter ASCII (a-z), this value will be written to DDR3
// if UART receives capital letter ASCII (A-Z), the small letter equivalent will be retrieved from DDR3 by doing
// a read request, once read data is available this will be sent to UART to be streamed out.
// THUS:
// Sendng "abcdefg" to the UART terminal will store that small latter to DDR3
// Then sending "ABCDEFG" to the UART terminal will return the small letter equivalent: "abcdefg"
always @(posedge i_controller_clk) begin always @(posedge i_controller_clk) begin
begin begin
i_wb_stb <= 0; i_wb_stb <= 0;
@ -51,13 +58,13 @@
i_wb_addr <= 0; i_wb_addr <= 0;
i_wb_data <= 0; i_wb_data <= 0;
if(!o_wb_stall && m_axis_tvalid) begin if(!o_wb_stall && m_axis_tvalid) begin
if(rd_data >= 97 && rd_data <= 122) begin //write if(rd_data >= 97 && rd_data <= 122) begin //write to DDR3 if ASCII is small letter
i_wb_stb <= 1; i_wb_stb <= 1;
i_wb_we <= 1; i_wb_we <= 1;
i_wb_addr <= ~rd_data ; i_wb_addr <= ~rd_data ;
i_wb_data <= rd_data; i_wb_data <= rd_data;
end end
else if(rd_data >= 65 && rd_data <= 90) begin //read else if(rd_data >= 65 && rd_data <= 90) begin //read from DDR3 if ASCII is capital letter
i_wb_stb <= 1; //make request i_wb_stb <= 1; //make request
i_wb_we <= 0; //read i_wb_we <= 0; //read
i_wb_addr <= ~(rd_data + 8'd32); i_wb_addr <= ~(rd_data + 8'd32);
@ -72,8 +79,8 @@
// Clock out ports // Clock out ports
.clk_out1(i_controller_clk), //83.333 Mhz .clk_out1(i_controller_clk), //83.333 Mhz
.clk_out2(i_ddr3_clk), // 333.333 MHz .clk_out2(i_ddr3_clk), // 333.333 MHz
.clk_out3(i_ref_clk), //200MHz .clk_out3(i_ddr3_clk_90), //200MHz
.clk_out4(i_ddr3_clk_90), // 333.333 MHz with 90degree shift .clk_out4(i_ref_clk), // 333.333 MHz with 90degree shift
// Status and control signals // Status and control signals
.reset(i_rst), .reset(i_rst),
.locked(clk_locked), .locked(clk_locked),
@ -81,6 +88,7 @@
.clk_in1(i_clk) .clk_in1(i_clk)
); );
// UART module from https://github.com/alexforencich/verilog-uart
uart #(.DATA_WIDTH(8)) uart_m uart #(.DATA_WIDTH(8)) uart_m
( (
.clk(i_controller_clk), .clk(i_controller_clk),
@ -95,7 +103,6 @@
.txd(tx), .txd(tx),
.prescale(1085) //9600 Baud Rate .prescale(1085) //9600 Baud Rate
); );
// DDR3 Controller // DDR3 Controller
ddr3_top #( ddr3_top #(
@ -164,7 +171,6 @@
.o_debug1(o_debug1), .o_debug1(o_debug1),
.o_debug2(), .o_debug2(),
.o_debug3() .o_debug3()
////////////////////////////////////
); );
endmodule endmodule