`timescale 1ns / 1ps
`define DLY #1
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer:
//
// Create Date:    14:23:43 11/04/2011
// Design Name:
// Module Name:    altro_emulator
// Project Name:
// Target Devices:
// Tool versions:
// Description:
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
//
//////////////////////////////////////////////////////////////////////////////////
module altro_emulator
  (
   input        rdoclk,
   input        cstbn,
   input        writen,

   output reg   ackn,
   output reg   trsfn,
   output       dstbn,

   inout [39:0] bd,

   input        reset
   );

  parameter RAND_SAMPLES = 1;
  parameter NUM_SAMPLES = 1022;

  reg [9:0]     num_samples; // Ammount of samples the emulator will send... per channel!

  reg [11:0]    ch_addr;
  reg [9:0]     trcfg;
  reg [19:0]    altro_reg0;
  reg [19:0]    altro_reg1;
  reg [39:0]    bdout;
  reg           bdout_en;
  reg           dstbn_en;
  reg [3:0]     clkcnt = 4'h0;

  assign dstbn = dstbn_en ? rdoclk : 1'b1;
  assign bd = bdout_en ? bdout : 40'hZ;

  parameter st0 = 0;
  parameter st1 = 1;
  parameter stc2 = 2;
  parameter stcw3 = 3;
  parameter stcw4 = 4;

  parameter stcr3 = 5;
  parameter stcr4 = 6;
  parameter stcr5 = 7;

  parameter strdo2 = 8;
  parameter strdo3 = 9;
  parameter strdo4 = 10;
  parameter strdo5 = 11;
  parameter strdo6 = 12;
  parameter strdo7 = 13;
  parameter strdo8 = 14;
  parameter strdo9 = 15;
  parameter strdo10 = 16;
  parameter stend = 20;

  reg [4:0]     st;
  reg [9:0]     samples_left;

  always @(posedge reset or posedge rdoclk)
    if(reset)
      begin
        trcfg                  <= /*`DLY*/ 10'h0;
        altro_reg0             <= /*`DLY*/ 20'h0;
        altro_reg1             <= /*`DLY*/ 20'h0;
        clkcnt                 <= /*`DLY*/ 4'h0;

        bdout                  <= /*`DLY*/ 40'h0;
        bdout_en               <= /*`DLY*/ 1'b0;
        ackn                   <= /*`DLY*/ 1'b1;
        trsfn                  <= /*`DLY*/ 1'b1;
        dstbn_en               <= /*`DLY*/ 1'b0;
        ch_addr                <= /*`DLY*/ 12'h0;
        st                     <= /*`DLY*/ st0;
      end

    else
      case(st)
        st0 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;
          if(cstbn)
            st                 <= /*`DLY*/ st0;
          else
            st                 <= /*`DLY*/ st1;
        end

        st1 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          if(bd[24:20]==5'h1A)
            st                 <= /*`DLY*/ strdo2;
          else
            st                 <= /*`DLY*/ stc2;
        end

        stc2 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          if(writen)
            st                 <= /*`DLY*/ stcr3;
          else
            st                 <= /*`DLY*/ stcw3;
        end

        stcw3 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          case(bd[24:20])
            5'h0a : trcfg      <= /*`DLY*/ bd[9:0];
            5'h01 : altro_reg0 <= /*`DLY*/ bd[19:0];
            5'h02 : altro_reg1 <= /*`DLY*/ bd[19:0];
            default : begin
              trcfg            <= /*`DLY*/ trcfg;
              altro_reg0       <= /*`DLY*/ altro_reg0;
              altro_reg1       <= /*`DLY*/ altro_reg1;
            end
          endcase

          st                   <= /*`DLY*/ stcw4;
        end

        stcw4 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          if(cstbn)
            st                 <= /*`DLY*/ st0;
          else
            st                 <= /*`DLY*/ stcw4;
        end

        stcr3 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          case(bd[24:20])
            5'h0a : bdout      <= /*`DLY*/ {30'h0,trcfg};
            5'h01 : bdout      <= /*`DLY*/ {20'h0, altro_reg0};
            5'h02 : bdout      <= /*`DLY*/ {20'h0, altro_reg1};
            default : begin
              bdout            <= /*`DLY*/ 40'h55005500;
            end
          endcase

          st                   <= /*`DLY*/ stcr4;
        end

        stcr4 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ bdout;
          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;
          st                   <= /*`DLY*/ stcr5;
        end

        stcr5 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ bdout;
          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;
          st                   <= /*`DLY*/ st0;
        end

        strdo2 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ bd[36:25];
          st                   <= /*`DLY*/ strdo3;
        end

        strdo3 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b0;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;

          if(cstbn)
            st                 <= /*`DLY*/ strdo4;
          else
            st                 <= /*`DLY*/ strdo3;
        end

        strdo4 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ clkcnt + 4'h1;


          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;

          if(clkcnt == 4'd4)
            st                 <= /*`DLY*/ strdo5;
          else
            st                 <= /*`DLY*/ strdo4;
        end

        strdo5 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;

          st                   <= /*`DLY*/ strdo6;
        end

        strdo6 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;
          num_samples          <= (RAND_SAMPLES)? $random % NUM_SAMPLES : NUM_SAMPLES;

          st                   <= /*`DLY*/ strdo7;
        end

        strdo7 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ 40'h0;
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b0;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;

          st                   <= /*`DLY*/(num_samples < 10'd5)?  strdo9 : strdo8;
          samples_left         <= /*`DLY*/ num_samples;
         // $display("%m Number of samples %d", num_samples);
        end


        strdo8 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ {samples_left - 10'd3, samples_left - 10'd2, samples_left - 10'd1, samples_left};
          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b0;
          dstbn_en             <= /*`DLY*/ 1'b1;
          ch_addr              <= /*`DLY*/ ch_addr;


          st                   <= (samples_left < 10'd9)?  strdo9 : strdo8 ;
          samples_left         <= /*`DLY*/ samples_left - 10'd4;
        end

        strdo9 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          case(samples_left)
            10'd1: bdout       <= /*`DLY*/ { 10'h2AA, 10'h2AA, 10'h2AA, samples_left};
            10'd2: bdout       <= /*`DLY*/ { 10'h2AA, 10'h2AA, samples_left - 10'd1, samples_left };
            10'd3: bdout       <= /*`DLY*/ { 10'h2AA, samples_left - 10'd2, samples_left - 10'd1, samples_left};
            10'd4: bdout       <= /*`DLY*/ { samples_left - 10'd3, samples_left - 10'd2, samples_left - 10'd1, samples_left};
            default: bdout     <= /*`DLY*/ 40'hX;
          endcase

          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b0;
          dstbn_en             <= /*`DLY*/ 1'b1;
          ch_addr              <= /*`DLY*/ ch_addr;


          st                   <= strdo10 ;
          samples_left         <= /*`DLY*/ samples_left - 4;
        end



        strdo10 : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          //bdout              <= /*`DLY*/ {14'h2aaa,10'h11,4'ha,ch_addr}; //trailer
          bdout                <= /*`DLY*/ {14'h2aaa, num_samples, 4'ha,ch_addr}; //trailer // 30 words. 28 samples, 1 timing info, 1 total samples. (assuming no zero suppresion is sent)
          //bdout              <= /*`DLY*/ {14'h2aaa,10'h05,4'ha,ch_addr}; //trailer
          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b0;
          dstbn_en             <= /*`DLY*/ 1'b1;
          ch_addr              <= /*`DLY*/ ch_addr;

          st                   <= /*`DLY*/ stend;
        end // case: strdo10

        stend : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ {40'hZ};
          bdout_en             <= /*`DLY*/ 1'b1;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b0;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ ch_addr;

          st                   <= /*`DLY*/ st0;
        end

        default : begin
          trcfg                <= /*`DLY*/ trcfg;
          altro_reg0           <= /*`DLY*/ altro_reg0;
          altro_reg1           <= /*`DLY*/ altro_reg1;
          clkcnt               <= /*`DLY*/ 4'h0;

          bdout                <= /*`DLY*/ 40'h0; //trailer
          bdout_en             <= /*`DLY*/ 1'b0;
          ackn                 <= /*`DLY*/ 1'b1;
          trsfn                <= /*`DLY*/ 1'b1;
          dstbn_en             <= /*`DLY*/ 1'b0;
          ch_addr              <= /*`DLY*/ 12'h0;

          st                   <= /*`DLY*/ st0;
          samples_left         <=  samples_left;
        end
      endcase

endmodule