cf.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 cf (
            // inputs:
             av_ctl_address,
             av_ctl_chipselect_n,
             av_ctl_read_n,
             av_ctl_write_n,
             av_ctl_writedata,
             av_ide_address,
             av_ide_chipselect_n,
             av_ide_read_n,
             av_ide_write_n,
             av_ide_writedata,
             av_reset_n,
             clk,
             detect_n,
             intrq,
             iordy,
             reset_n,

            // outputs:
             addr,
             atasel_n,
             av_ctl_irq,
             av_ctl_readdata,
             av_ide_irq,
             av_ide_readdata,
             cs_n,
             data_cf,
             iord_n,
             iowr_n,
             power,
             reset_n_cf,
             rfu,
             we_n
          );

  output  [ 10: 0] addr;
  output           atasel_n;
  output           av_ctl_irq;
  output  [  3: 0] av_ctl_readdata;
  output           av_ide_irq;
  output  [ 15: 0] av_ide_readdata;
  output  [  1: 0] cs_n;
  inout   [ 15: 0] data_cf;
  output           iord_n;
  output           iowr_n;
  output           power;
  output           reset_n_cf;
  output           rfu;
  output           we_n;
  input   [  1: 0] av_ctl_address;
  input            av_ctl_chipselect_n;
  input            av_ctl_read_n;
  input            av_ctl_write_n;
  input   [  3: 0] av_ctl_writedata;
  input   [  3: 0] av_ide_address;
  input            av_ide_chipselect_n;
  input            av_ide_read_n;
  input            av_ide_write_n;
  input   [ 15: 0] av_ide_writedata;
  input            av_reset_n;
  input            clk;
  input            detect_n;
  input            intrq;
  input            iordy;
  input            reset_n;

  wire    [ 10: 0] addr;
  wire             atasel_n;
  reg              av_ctl_irq;
  reg     [  3: 0] av_ctl_readdata;
  wire             av_ide_irq;
  wire    [ 15: 0] av_ide_readdata;
  wire    [  1: 0] cs_n;
  wire             ctl_hi_write_strobe;
  reg              ctl_irq_en_reg;
  wire             ctl_lo_read_strobe;
  wire             ctl_lo_write_strobe;
  wire    [  3: 0] ctl_read_mux;
  reg              d1_present_reg;
  wire    [ 15: 0] data_cf;
  reg              ide_irq_en_reg;
  wire             iord_n;
  wire             iowr_n;
  wire             power;
  reg              power_reg;
  reg     [ 16: 0] present_counter;
  reg              present_reg;
  wire             reset_n_cf;
  reg              reset_reg;
  wire             rfu;
  wire             we_n;
  assign atasel_n = 1'b0;
  assign we_n = 1'b1;
  assign rfu = 1'b1;
  assign addr[10 : 3] = 8'h00;
  assign addr[2 : 0] = av_ide_address[2 : 0];
  assign iord_n = av_ide_read_n;
  assign iowr_n = av_ide_write_n;
  assign cs_n[0] = ~av_ide_chipselect_n ? (~av_ide_address[3] ? 1'b0 : 1'b1) : 1'b1;
  assign cs_n[1] = ~av_ide_chipselect_n ? ( av_ide_address[3] ? 1'b0 : 1'b1) : 1'b1;
  assign av_ide_readdata = present_reg ? data_cf : 16'hFFFF;
  assign data_cf = (~av_ide_write_n && present_reg) ? av_ide_writedata :16'hZZZZ;
  assign power = (power_reg && present_reg) ? 1'b1 : 1'b0;
  assign reset_n_cf = (reset_reg || ~av_reset_n || ~present_reg) ? 1'b0 : 1'b1;
  assign av_ide_irq = (ide_irq_en_reg && present_reg) ? intrq : 1'b0;
  assign ctl_lo_write_strobe = ~av_ctl_chipselect_n && ~av_ctl_write_n && 
    (av_ctl_address == 4'h0);

  assign ctl_hi_write_strobe = ~av_ctl_chipselect_n && ~av_ctl_write_n &&
    (av_ctl_address == 4'h1);

  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          ctl_irq_en_reg <= 0;
      else if (ctl_lo_write_strobe)
          ctl_irq_en_reg <= av_ctl_writedata[3];
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          reset_reg <= 0;
      else if (ctl_lo_write_strobe)
          reset_reg <= av_ctl_writedata[2];
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          power_reg <= 0;
      else if (ctl_lo_write_strobe)
          power_reg <= av_ctl_writedata[1];
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          ide_irq_en_reg <= 0;
      else if (ctl_hi_write_strobe)
          ide_irq_en_reg <= av_ctl_writedata[0];
    end


  assign ctl_read_mux = (av_ctl_address == 2'b00)? {ctl_irq_en_reg,
    reset_reg,
    power_reg,
    present_reg} :
    (av_ctl_address == 2'b01)? {3'h0,
    ide_irq_en_reg} :
    (av_ctl_address == 2'b10)? 4'h0 :
    4'h0;

  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          av_ctl_readdata <= 0;
      else if (1)
          av_ctl_readdata <= ctl_read_mux;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          present_counter <= 0;
      else if (1)
          if (detect_n)
              present_counter <= 0;
          else 
            present_counter <= present_counter + 1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          present_reg <= 0;
      else if (1)
          if (detect_n)
              present_reg <= 0;
          else if (present_counter == 85000)
              present_reg <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          d1_present_reg <= 0;
      else if (1)
          d1_present_reg <= present_reg;
    end


  assign ctl_lo_read_strobe = ~av_ctl_chipselect_n && ~av_ctl_read_n && 
    (av_ctl_address == 4'h0);

  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          av_ctl_irq <= 0;
      else if (ctl_irq_en_reg)
          if (ctl_lo_read_strobe)
              av_ctl_irq <= 0;
          else if (d1_present_reg ^ present_reg)
              av_ctl_irq <= -1;
    end


  //ctl, which is an e_avalon_slave
  //ide, which is an e_avalon_slave


endmodule