Verilog设计要求： 1、东西、南北各有红、黄、绿指示灯 2、绿灯、黄灯和红灯的持续时间分别为40s、5s和45s

好的，以下是一个简单的Verilog代码来实现一个包含东西、南北各有红、黄、绿指示灯的交通灯系统，并且绿灯、黄灯和红灯的持续时间分别为40秒、5秒和45秒：

module traffic_light(
  input clk,
  output reg EW_red,
  output reg EW_yellow,
  output reg EW_green,
  output reg NS_red,
  output reg NS_yellow,
  output reg NS_green
);

reg [3:0] state;
reg [5:0] counter;

localparam S_EW_GREEN = 4'b0001;
localparam S_EW_YELLOW = 4'b0010;
localparam S_NS_RED = 4'b0011;
localparam S_NS_GREEN = 4'b0100;
localparam S_NS_YELLOW = 4'b0101;
localparam S_EW_RED = 4'b0110;

always @(posedge clk) begin
  counter <= counter + 1;
  case(state)
    S_EW_GREEN: begin
      EW_red <= 0;
      EW_yellow <= 0;
      EW_green <= 1;
      NS_red <= 1;
      NS_yellow <= 0;
      NS_green <= 0;
      if(counter == 40000000) begin
        state <= S_EW_YELLOW;
        counter <= 0;
      end
    end
    S_EW_YELLOW: begin
      EW_red <= 0;
      EW_yellow <= 1;
      EW_green <= 0;
      NS_red <= 1;
      NS_yellow <= 0;
      NS_green <= 0;
      if(counter == 5000000) begin
        state <= S_NS_RED;
        counter <= 0;
      end
    end
    S_NS_RED: begin
      EW_red <= 1;
      EW_yellow <= 0;
      EW_green <= 0;
      NS_red <= 0;
      NS_yellow <= 0;
      NS_green <= 1;
      if(counter == 45000000) begin
        state <= S_NS_GREEN;
        counter <= 0;
      end
    end
    S_NS_GREEN: begin
      EW_red <= 1;
      EW_yellow <= 0;
      EW_green <= 0;
      NS_red <= 0;
      NS_yellow <= 0;
      NS_green <= 1;
      if(counter == 40000000) begin
        state <= S_NS_YELLOW;
        counter <= 0;
      end
    end
    S_NS_YELLOW: begin
      EW_red <= 1;
      EW_yellow <= 0;
      EW_green <= 0;
      NS_red <= 0;
      NS_yellow <= 1;
      NS_green <= 0;
      if(counter == 5000000) begin
        state <= S_EW_RED;
        counter <= 0;
      end
    end
    S_EW_RED: begin
      EW_red <= 1;
      EW_yellow <= 0;
      EW_green <= 0;
      NS_red <= 0;
      NS_yellow <= 0;
      NS_green <= 1;
      if(counter == 45000000) begin
        state <= S_EW_GREEN;
        counter <= 0;
      end
    end
  endcase
end

endmodule

这个代码使用一个有限状态机来控制交通灯的状态，包括东西和南北方向的红、黄、绿灯。在每个时钟周期的上升沿，状态机会根据当前的状态来决定下一个状态，并相应地控制交通灯的输出。同时，还使用了一个计数器来计算绿灯、黄灯和红灯的持续时间，并在达到预设时间后切换到下一个状态。