Subversion Repositories zet86

`timescale 10ns/100ps
 
module testbench;
 
  // Net declarations
  wire [15:0] dat_o;
  wire [15:0] mem_dat_i, io_dat_i, dat_i;
  wire [19:1] adr;
  wire        we;
  wire        tga;
  wire [ 1:0] sel;
  wire        stb;
  wire        cyc;
  wire        ack, mem_ack, io_ack;
 
  reg         clk;
  reg         rst;
 
  reg  [15:0] io_reg;
 
  // Module instantiations
  memory mem0 (
    .wb_clk_i (clk),
    .wb_rst_i (rst),
    .wb_dat_i (dat_o),
    .wb_dat_o (mem_dat_i),
    .wb_adr_i (adr),
    .wb_we_i  (we),
    .wb_sel_i (sel),
    .wb_stb_i (stb & !tga),
    .wb_cyc_i (cyc & !tga),
    .wb_ack_o (mem_ack)
  );
 
  cpu cpu0 (
    .wb_clk_i (clk),
    .wb_rst_i (rst),
    .wb_dat_i (dat_i),
    .wb_dat_o (dat_o),
    .wb_adr_o (adr),
    .wb_we_o  (we),
    .wb_tga_o (tga),
    .wb_sel_o (sel),
    .wb_stb_o (stb),
    .wb_cyc_o (cyc),
    .wb_ack_i (ack)
  );
 
  // Assignments
  assign io_dat_i = (adr[15:1]==15'h5b) ? { io_reg[7:0], 8'h0 }
    : ((adr[15:1]==15'h5c) ? { 8'h0, io_reg[15:8] } : 16'h0);
  assign dat_i = tga ? io_dat_i : mem_dat_i;
 
  assign ack    = tga ? io_ack : mem_ack;
  assign io_ack = stb;
 
  // Behaviour
  // IO Stub
  always @(posedge clk)
    if (adr[15:1]==15'h5b && sel[1] && cyc && stb)
      io_reg[7:0] <= dat_o[15:8];
    else if (adr[15:1]==15'h5c & sel[0] && cyc && stb)
      io_reg[15:8] <= dat_o[7:0];
 
  always #1 clk = ~clk;
 
  initial 
    begin
         clk <= 1'b1;
         rst <= 1'b0;
      #5 rst <= 1'b1;
      #2 rst <= 1'b0;
    end
 
endmodule