git.zerfleddert.de Git - fpga-games/blob - galaxian/src/mc_sound_a.v

   1 //===============================================================================
   2 // FPGA MOONCRESTA SOUND I/F
   3 //
   4 // Version : 1.00
   5 //
   6 // Copyright(c) 2004 Katsumi Degawa , All rights reserved
   7 //
   8 // Important !
   9 //
  10 // This program is freeware for non-commercial use.
  11 // An author does no guarantee about this program.
  12 // You can use this under your own risk.
  13 //
  14 //================================================================================
  15
  16
  17 module mc_sound_a(
  18
  19 I_CLK_12M,
  20 I_CLK_6M,
  21 I_H_CNT1,
  22 I_BD,
  23 I_PITCHn,
  24 I_VOL1,
  25 I_VOL2,
  26
  27 O_SDAT,
  28 O_DO
  29
  30 );
  31
  32 input  I_CLK_12M;
  33 input  I_CLK_6M;
  34 input  I_H_CNT1;
  35 input  [7:0]I_BD;
  36 input  I_PITCHn;
  37 input  I_VOL1;
  38 input  I_VOL2;
  39
  40 output [3:0]O_DO;
  41 output [7:0]O_SDAT;
  42
  43 reg    W_PITCHn;
  44 reg    W_89K_LDn;
  45 reg    [7:0]W_89K_Q;
  46 reg    [7:0]W_89K_LDATA;
  47 reg    [3:0]W_6T_Q;
  48
  49 always@(posedge I_CLK_12M)
  50 begin
  51    W_PITCHn  <= I_PITCHn;
  52    W_89K_LDn <= ~(&W_89K_Q[7:0]);
  53 end
  54
  55 // Parts 9J
  56 always@(posedge W_PITCHn) W_89K_LDATA <= I_BD;
  57
  58 always@(posedge I_H_CNT1)
  59 begin
  60    if(~W_89K_LDn)
  61       W_89K_Q <= W_89K_LDATA;
  62    else
  63       W_89K_Q <= W_89K_Q + 1;
  64 end
  65
  66 always@(negedge W_89K_LDn) W_6T_Q <= W_6T_Q + 1;
  67 assign O_DO = W_6T_Q;
  68
  69 reg    [7:0]W_SDAT0;
  70 reg    [7:0]W_SDAT2;
  71 reg    [7:0]W_SDAT3;
  72 always@(posedge I_CLK_6M)
  73 begin
  74    W_SDAT0 <= W_6T_Q[0]==1'b0 ? 8'd0 : 8'd42 ;
  75    W_SDAT2 <= W_6T_Q[2]==1'b0 ? 8'd0 : I_VOL1 ? 8'd105 : 8'd57 ;
  76    W_SDAT3 <= W_6T_Q[3]==1'b0 ? 8'd0 : I_VOL2 ? 8'd72  : 8'd0  ;
  77 end
  78
  79 assign O_SDAT = W_SDAT0 + W_SDAT2 + W_SDAT3 + 8'd20 ;
  80
  81
  82 endmodule