Soundcore.v

   1 `define ADDR_NR50 16'hFF24
   2 `define ADDR_NR51 16'hFF25
   3 `define ADDR_NR52 16'hFF26
   4
   5 module Soundcore(
   6         input core_clk,
   7         input wr,
   8         input rd,
   9         input [15:0] addr,
  10         inout [7:0] data,
  11         output reg snd_data_l,
  12         output reg snd_data_r
  13         );
  14
  15         reg [7:0] nr50 = 8'h00, nr51 = 8'h00, nr52 = 8'hF0;
  16         reg [3:0] pwmcnt = 4'b0000;
  17         reg [4:0] cntclk = 5'b00000;
  18         reg [13:0] lenclk;
  19         wire [3:0] sndout1,sndout2,sndout3,sndout4;
  20         wire [3:0] right_snd =
  21                 (nr51[0] ? sndout1 : 4'b0) +
  22                 (nr51[1] ? sndout2 : 4'b0) +
  23                 (nr51[2] ? sndout3 : 4'b0) +
  24                 (nr51[3] ? sndout4 : 4'b0);
  25         wire [3:0] left_snd =
  26                 (nr51[4] ? sndout1 : 4'b0) +
  27                 (nr51[5] ? sndout2 : 4'b0) +
  28                 (nr51[6] ? sndout3 : 4'b0) +
  29                 (nr51[7] ? sndout4 : 4'b0);
  30         assign sndout3 = 0;
  31         assign sndout4 = 0;
  32
  33         assign data = rd ?
  34                          addr == `ADDR_NR50 ? nr50 :
  35                          addr == `ADDR_NR51 ? nr51 :
  36                          addr == `ADDR_NR52 ? nr52 : 8'bzzzzzzzz
  37                       : 8'bzzzzzzzz;
  38
  39         always @ (negedge core_clk) begin
  40                 if(wr) begin
  41                         case(addr)
  42                         `ADDR_NR50: nr50 <= data;
  43                         `ADDR_NR51: nr51 <= data;
  44                         `ADDR_NR52: nr52 <= {data[7],7'b1111111};
  45                         endcase
  46                 end
  47                 cntclk <= cntclk + 1;
  48                 lenclk <= lenclk + 1;
  49                 pwmcnt <= pwmcnt + 1;
  50                 snd_data_l <= (pwmcnt <= left_snd) ? 1 : 0;
  51                 snd_data_r <= (pwmcnt <= right_snd) ? 1 : 0;
  52         end
  53
  54         Sound1 s1(
  55                 .core_clk(core_clk),
  56                 .wr(wr),
  57                 .rd(rd),
  58                 .addr(addr),
  59                 .data(data),
  60                 .cntclk(cntclk[4]),
  61                 .lenclk(lenclk[13]),
  62                 .en(nr52[7]),
  63                 .snd_data(sndout1)
  64         );
  65
  66         Sound2 s2(
  67                 .core_clk(core_clk),
  68                 .wr(wr),
  69                 .rd(rd),
  70                 .addr(addr),
  71                 .data(data),
  72                 .cntclk(cntclk[4]),
  73                 .lenclk(lenclk[13]),
  74                 .en(nr52[7]),
  75                 .snd_data(sndout2)
  76         );
  77
  78 endmodule