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代码：

测试台.v：

// ============================================================
//
// Traffic light tester module.
//
// We clock the device as usual, supply reset, and eventually "push
// the walk button" to activate the traffic light.
//
// ============================================================

// `timescale 1 ns / 1 ns

module TestBench;

   reg  clk;     // Clock into the FPGA
   reg  walk;    // A button that causes the walk light to go on
   reg  reset;   // The reset line to your design

   wire green;   // The green light on Dodge Street
   wire yellow;  // The yellow light on ...
   wire red;     // The red light on ...
   wire go;      // The walk light for the pedestrian
   wire stop;    // The "don't walk" light

   // Here is your FPGA chip
   Traffic yourChip( reset, clk, walk, green, yellow, red, go, stop );
   // Provide clocking to the FPGA
   always
      begin
      #10 clk = ~clk;
      end


   // Start up code.
   initial
     begin
    clk = 0;
    walk = 0;
    reset = 1;
    #100 reset = 0;
     end

   // Eventually we want to "push the walk button" which causes the
   // traffic lights to cycle yellow, red, then back to green.
   // Also, we want to stop the sim at some point too. 
   initial
     begin
    #1000 walk = 1;
    #100  walk = 0;
    #100000 $stop;
     end

endmodule // QuasiTestBench

时钟分频器.v：

module clockDivider(
    input wire clock, 
    input wire reset, 
    output wire dividedClk
    );

reg [127:0] counter;

always @(posedge clock or posedge reset)
    begin
        if(reset == 1)
            counter <=0;
        else
            counter <= counter + 1;
        end
    assign dividedClk = counter[127];

endmodule

交通.v：

module Traffic( reset, clock, walk, green, yellow, red, walkLight, handLight);
input wire reset;
input wire clock;
input wire walk;

output reg green, yellow, red, walkLight, handLight;

reg[2:0] state;
reg[3:0] count;
//we want some kind of state machine here.
//let's define some states
parameter s0 = 0  //green
    , s1=1         //yellow
    , s2=2;         //red 
reg[3:0] timeButtonPushed;

//clockDivider myClock(clock, reset);

always @(posedge clock or posedge reset)
    begin
            if (reset == 1)
                begin
                    state <= s0;  //default to green light on reset.
                    handLight = 1;
                    green = 1;
                    timeButtonPushed = 0;
                    count <= 0;
                end
            else
                case(state)
                    s0:
                        begin
                            if(walk == 1)
                                begin
                                    //compute 10s timeout before switch to yellow
                                    //requires us to capture some info about time button pushed
                                    timeButtonPushed = count;  //record time button was pushed
                                end
                            else
                                if(timeButtonPushed == (count - 10))  
                                    begin
                                        state = s1;  //We've reached countdown state set light to yellow.
                                        green = 0;
                                        yellow = 1;
                                    end
                            count = count + 1;
                        end                 
                    s1:
                        begin
                            if(timeButtonPushed == (count - 15))  //We've reached timeout for yellow light.
                                begin   
                                    state = s2;  //move to red state
                                    handLight = 0;
                                    walkLight = 1;
                                    red = 1;
                                end
                            count = count + 1;
                        end
                    s2:
                        begin
                            if(timeButtonPushed == count - 45)
                                begin
                                    state = s0; //move back to green state
                                    red = 0;
                                    walkLight = 0;
                                    handLight = 1;
                                    green = 0;
                                    timeButtonPushed = 0;
                                end
                            count = count + 1;
                        end             
                    default: state <= s0;
                endcase

    end

endmodule

我试图在TestBench中实例化clockDivider，我也试图在Traffic.v中实例化它，试图将它插入到Traffic.v中的时钟和输入clk线之间

理想情况下，我想要一个解决方案，向我展示正确连接clockDivider的正确方法，但是如果有其他方法——即使是hack-ish来完成它，我会很感激。

我也试过完全忘记clockDivider.v并用这个替换时钟代码：

 reg [127:0] counter;
        always
         begin
            if(reset == 1)
                counter <=0;
            else if(counter == 126)
                assign clk = ~clk;
            else
                counter <= counter + 1;
            end

但这似乎也失败了。

4

1 回答 1

0

首先，在您的示例实例化中，您没有将任何信号连接到分频时钟输出。因此，很难看出你想用它做什么。您可以省略连接，但您需要分隔逗号。尝试：clockDivider myClock(clock, reset,);

其次，用逻辑生成时钟是糟糕的设计——你会在时序方面遇到重大问题。逻辑信号无法正确加载到时钟树网络上，因此您会得到较大的时钟偏移。相反，将您的计数器用作任何“较慢”寄存器的启用信号并使用全局时钟，或使用 PLL/DLL 生成新的（较慢的）时钟信号。

作为第一个例子：

reg enable;
reg [127:0] counter;
parameter NUMBEROFCYCLES = 100;

always @(posedge clk)
begin
    if (reset) enable <= 0;
    else if (counter == NUMBEROFCYCLES) enable <= 1;
    else enable <= 0;
end

always @(posedge clk)
begin
    if (reset) counter <= 0;
    else if (counter == NUMBEROFCYCLES) counter <= 0;
    else counter <= counter + 1;
end

always @(posedge clk)
begin
    if (reset) <<reset some signals>>
    else if (enable) <<change some signals>>
    else <<signals <= signals>>
end
于 2015-05-10T02:06:04.750 回答