1

我正在开发一个程序,该程序将采用 BCD 值,将其转换为二进制,并将给定值倒计时为 0。BCD 转换模块运行良好,但似乎我的“微波”模块没有被调用。

我这个程序的输出是:

time = xxxxxxxx bcdtime = 0001 0010

time = 00001100 bcdtime = 0001 0010

我可以看到转换,但倒计时不会发生。谁能解释我可能出错的地方或指出可以帮助我回答这个问题的资源方向?我的代码如下:

module bcd_to_bin(bintime,bcdtime1,bcdtime0);
  input [3:0] bcdtime1,bcdtime0;
  output [7:0] bintime;

  assign bintime = (bcdtime1 * 4'b1010) + {3'b0, bcdtime0};
endmodule

module microwave(bintimeout, Clk, Start, Stop, bintime, status);
    input [7:0] bintime;
    input Clk, Start, Stop;
    output reg [7:0] bintimeout;
    output reg status;
    
    
 always @ (posedge Start)
    begin
        assign bintimeout = bintime;
    end 
    
 always @ (posedge Clk)

  begin 
    bintimeout = bintimeout - 1;
  end
endmodule


module t_microwave;

    wire status;
    wire [7:0] bintimeout;
    reg Clk=1; reg Start, Stop;
    reg [3:0] bcdtime1, bcdtime0;
    wire [7:0] bintime;
    
    microwave M2 (bintimeout, Clk, Start, Stop, bintime, status);
    bcd_to_bin M3 (bintime,bcdtime1,bcdtime0);
    
    
    
     always #10 Clk = ~Clk;
    initial
      begin
        
        Start = 0; Stop = 0; bcdtime1 = 4'b0001; bcdtime0 = 4'b0010;
        #10 Start = 1; #10 Start = 0;

        
      end       

    initial #10000 $finish;

    initial
      begin
        $monitor ("time = %b, bcdtime = %b %b ", bintimeout, bcdtime1, bcdtime0);
      end
endmodule
4

1 回答 1

2

您的代码存在一些问题。

如果您想保证您的设计能够捕捉到Start脉冲,您应该确保它在一个时钟周期内保持高电平 (20)。改变:

    #10 Start = 1; #10 Start = 0;

至:

    #10 Start = 1; #20 Start = 0;

microwave模块中,你应该bintimeout在一个always块中赋值,而不是两个,并且不需要在块assign内使用关键字always。此外,良好的编码实践建议<=对顺序逻辑使用非阻塞赋值 ( )。这是编写模块的更好方法:

module microwave(bintimeout, Clk, Start, Stop, bintime, status);
    input [7:0] bintime;
    input Clk, Start, Stop;
    output reg [7:0] bintimeout;
    output reg status;
    
    always @ (posedge Clk) begin
        if (Start) begin
            bintimeout <= bintime;
        end else begin
            bintimeout <= bintimeout - 1;
        end
    end
endmodule

这是现在的输出,显示倒计时:

time = xxxxxxxx, bcdtime = 0001 0010 
time = 00001100, bcdtime = 0001 0010 
time = 00001011, bcdtime = 0001 0010 
time = 00001010, bcdtime = 0001 0010 
time = 00001001, bcdtime = 0001 0010 
time = 00001000, bcdtime = 0001 0010 
time = 00000111, bcdtime = 0001 0010 
time = 00000110, bcdtime = 0001 0010 
time = 00000101, bcdtime = 0001 0010 
time = 00000100, bcdtime = 0001 0010 
time = 00000011, bcdtime = 0001 0010 
time = 00000010, bcdtime = 0001 0010 
time = 00000001, bcdtime = 0001 0010 
time = 00000000, bcdtime = 0001 0010 
time = 11111111, bcdtime = 0001 0010 
time = 11111110, bcdtime = 0001 0010 
于 2021-11-22T00:54:53.220 回答