jtag_uart.v

这个是基于NIOS II的FPGA平台的一个CF卡的接口模块

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// synthesis translate_off
`timescale 1ns / 100ps
// synthesis translate_on
module jtag_uart_log_module (
                              // inputs:
                               clk,
                               data,
                               strobe,
                               valid
                            );

  input            clk;
  input   [  7: 0] data;
  input            strobe;
  input            valid;


//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
   reg [31:0] text_handle; // for $fopen
   initial text_handle = $fopen ("C:/designs/cf_tests/to_nios_forum/std_cf_2c35/std_2C35_sim/jtag_uart_output_stream.dat");

   always @(posedge clk) begin
      if (valid && strobe) begin
	 $fwrite (text_handle, "%b\n", data);
          // echo raw binary strings to file as ascii to screen
         $write("%s", ((data == 8'hd) ? 8'ha : data));
                     
	 // non-standard; poorly documented; required to get real data stream.
	 $fflush (text_handle);
      end
   end // clk


//////////////// END SIMULATION-ONLY CONTENTS

//synthesis translate_on


endmodule


module jtag_uart_sim_scfifo_w (
                                // inputs:
                                 clk,
                                 fifo_wdata,
                                 fifo_wr,

                                // outputs:
                                 fifo_FF,
                                 r_dat,
                                 wfifo_empty,
                                 wfifo_used
                              );

  output           fifo_FF;
  output  [  7: 0] r_dat;
  output           wfifo_empty;
  output  [  5: 0] wfifo_used;
  input            clk;
  input   [  7: 0] fifo_wdata;
  input            fifo_wr;

  wire             fifo_FF;
  wire    [  7: 0] r_dat;
  wire             wfifo_empty;
  wire    [  5: 0] wfifo_used;

//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
  //jtag_uart_log, which is an e_log
  jtag_uart_log_module jtag_uart_log
    (
      .clk    (clk),
      .data   (fifo_wdata),
      .strobe (fifo_wr),
      .valid  (fifo_wr)
    );

  assign wfifo_used = {6{1'b0}};
  assign r_dat = {8{1'b0}};
  assign fifo_FF = 1'b0;
  assign wfifo_empty = 1'b1;

//////////////// END SIMULATION-ONLY CONTENTS

//synthesis translate_on


endmodule


module jtag_uart_scfifo_w (
                            // inputs:
                             clk,
                             fifo_wdata,
                             fifo_wr,
                             rd_wfifo,

                            // outputs:
                             fifo_FF,
                             r_dat,
                             wfifo_empty,
                             wfifo_used
                          );

  output           fifo_FF;
  output  [  7: 0] r_dat;
  output           wfifo_empty;
  output  [  5: 0] wfifo_used;
  input            clk;
  input   [  7: 0] fifo_wdata;
  input            fifo_wr;
  input            rd_wfifo;

  wire             fifo_FF;
  wire    [  7: 0] r_dat;
  wire             wfifo_empty;
  wire    [  5: 0] wfifo_used;

//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
  jtag_uart_sim_scfifo_w the_jtag_uart_sim_scfifo_w
    (
      .clk         (clk),
      .fifo_FF     (fifo_FF),
      .fifo_wdata  (fifo_wdata),
      .fifo_wr     (fifo_wr),
      .r_dat       (r_dat),
      .wfifo_empty (wfifo_empty),
      .wfifo_used  (wfifo_used)
    );


//////////////// END SIMULATION-ONLY CONTENTS

//synthesis translate_on
//synthesis read_comments_as_HDL on
//  scfifo wfifo
//    (
//      .clock (clk),
//      .data (fifo_wdata),
//      .empty (wfifo_empty),
//      .full (fifo_FF),
//      .q (r_dat),
//      .rdreq (rd_wfifo),
//      .usedw (wfifo_used),
//      .wrreq (fifo_wr)
//    );
//
//  defparam wfifo.lpm_hint = "RAM_BLOCK_TYPE=AUTO",
//           wfifo.lpm_numwords = 64,
//           wfifo.lpm_showahead = "OFF",
//           wfifo.lpm_type = "scfifo",
//           wfifo.lpm_width = 8,
//           wfifo.lpm_widthu = 6,
//           wfifo.overflow_checking = "OFF",
//           wfifo.underflow_checking = "OFF",
//           wfifo.use_eab = "ON";
//
//synthesis read_comments_as_HDL off


endmodule


module jtag_uart_drom_module (
                               // inputs:
                                clk,
                                incr_addr,
                                reset_n,

                               // outputs:
                                new_rom,
                                num_bytes,
                                q,
                                safe
                             );

  parameter POLL_RATE = 100;


  output           new_rom;
  output  [ 31: 0] num_bytes;
  output  [  7: 0] q;
  output           safe;
  input            clk;
  input            incr_addr;
  input            reset_n;

  reg     [ 11: 0] address;
  reg              d1_pre;
  reg              d2_pre;
  reg              d3_pre;
  reg              d4_pre;
  reg              d5_pre;
  reg              d6_pre;
  reg              d7_pre;
  reg              d8_pre;
  reg              d9_pre;
  reg     [  7: 0] mem_array [2047: 0];
  reg     [ 31: 0] mutex [  1: 0];
  reg              new_rom;
  wire    [ 31: 0] num_bytes;
  reg              pre;
  wire    [  7: 0] q;
  wire             safe;

//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
  assign q = mem_array[address];
  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
        begin
          d1_pre <= 0;
          d2_pre <= 0;
          d3_pre <= 0;
          d4_pre <= 0;
          d5_pre <= 0;
          d6_pre <= 0;
          d7_pre <= 0;
          d8_pre <= 0;
          d9_pre <= 0;
          new_rom <= 0;
        end
      else if (1)
        begin
          d1_pre <= pre;
          d2_pre <= d1_pre;
          d3_pre <= d2_pre;
          d4_pre <= d3_pre;
          d5_pre <= d4_pre;
          d6_pre <= d5_pre;
          d7_pre <= d6_pre;
          d8_pre <= d7_pre;
          d9_pre <= d8_pre;
          new_rom <= d9_pre;
        end
    end



   assign     num_bytes = mutex[1];
                   reg        safe_delay;
   reg [31:0] poll_count;
   reg [31:0] mutex_handle;
   wire       interactive = 1'b0 ; // '
   assign     safe = (address < mutex[1]);

   initial poll_count = POLL_RATE;

   always @(posedge clk or negedge reset_n) begin
      if (reset_n !== 1) begin
         safe_delay <= 0;
      end else begin
         safe_delay <= safe;
      end
   end // safe_delay

   always @(posedge clk or negedge reset_n) begin
      if (reset_n !== 1) begin  // dont worry about null _stream.dat file
         address <= 0;
         mem_array[0] <= 0;
         mutex[0] <= 0;
         mutex[1] <= 0;
         pre <= 0;
      end else begin            // deal with the non-reset case
         pre <= 0;
         if (incr_addr && safe) address <= address + 1;
         if (mutex[0] && !safe && safe_delay) begin
            // and blast the mutex after falling edge of safe if interactive
            if (interactive) begin
               mutex_handle = $fopen ("C:/designs/cf_tests/to_nios_forum/std_cf_2c35/std_2C35_sim/jtag_uart_input_mutex.dat");
               $fdisplay (mutex_handle, "0");
               $fclose (mutex_handle);
               // $display ($stime, "\t%m:\n\t\tMutex cleared!");
            end else begin
               // sleep until next reset, do not bash mutex.
               wait (!reset_n);
            end
         end // OK to bash mutex.
         if (poll_count < POLL_RATE) begin // wait
            poll_count = poll_count + 1;
         end else begin         // do the interesting stuff.
            poll_count = 0;
            $readmemh ("C:/designs/cf_tests/to_nios_forum/std_cf_2c35/std_2C35_sim/jtag_uart_input_mutex.dat", mutex);
            if (mutex[0] && !safe) begin
            // read stream into mem_array after current characters are gone!
               // save mutex[0] value to compare to address (generates 'safe')
               mutex[1] <= mutex[0];
               // $display ($stime, "\t%m:\n\t\tMutex hit: Trying to read %d bytes...", mutex[0]);
               $readmemb("C:/designs/cf_tests/to_nios_forum/std_cf_2c35/std_2C35_sim/jtag_uart_input_stream.dat", mem_array);
               // bash address and send pulse outside to send the char:
               address <= 0;
               pre <= -1;
            end // else mutex miss...
         end // poll_count
      end // reset
   end // posedge clk


//////////////// END SIMULATION-ONLY CONTENTS

//synthesis translate_on


endmodule


module jtag_uart_sim_scfifo_r (
                                // inputs:
                                 clk,
                                 fifo_rd,
                                 rst_n,

                                // outputs:
                                 fifo_EF,
                                 fifo_rdata,
                                 rfifo_full,
                                 rfifo_used
                              );

  output           fifo_EF;
  output  [  7: 0] fifo_rdata;
  output           rfifo_full;
  output  [  5: 0] rfifo_used;
  input            clk;
  input            fifo_rd;
  input            rst_n;

  reg     [ 31: 0] bytes_left;
  wire             fifo_EF;
  reg              fifo_rd_d;
  wire    [  7: 0] fifo_rdata;
  wire             new_rom;
  wire    [ 31: 0] num_bytes;
  wire    [  6: 0] rfifo_entries;
  wire             rfifo_full;
  wire    [  5: 0] rfifo_used;
  wire             safe;

//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
  //jtag_uart_drom, which is an e_drom
  jtag_uart_drom_module jtag_uart_drom
    (
      .clk       (clk),
      .incr_addr (fifo_rd_d),
      .new_rom   (new_rom),