traffic-light-control-system/Mode1.v at main · yuxincs/traffic-light-control-system · GitHub

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`timescale 1ns / 1ps

module Mode1(
    output reg[1:0] light,
    output reg[4:0] lightTime,
    output reg feedback,
    output reg [1:0]currentState,
    input [1:0]lastState,
    input set,
    input enb,
    input peak,
    input clk
    );
    parameter RED = 2'b00;
    parameter YELLOW = 2'b01;
    parameter GREEN = 2'b10;
    parameter UNDEFINED = 2'b11;

    wire div;
    FreqDiv_1s freqDiv(div,clk);

    always@(posedge div) begin
        feedback <= 1'b0;

        //Sync the global status
        if(!enb) begin
            case(lastState)
                GREEN: begin
                    light <= YELLOW;
                    lightTime <= 5'd5;
                end
                YELLOW: begin
                    light <= RED;
                    if(peak)
                        lightTime <= 5'd8;
                    else
                        lightTime <= 5'd16;
                end
                RED: begin
                    light <= GREEN;
                    lightTime <= 5'd16;
                end
            endcase
        end

        else if(set && enb) begin
            case(light)
                GREEN: begin
                    currentState <= GREEN;
                    if(lightTime == 5'd1) begin
                        light <= YELLOW;
                        lightTime <= 5'd5;
                        feedback <= 1'b1;
                    end
                    else
                        lightTime <= lightTime - 5'd1;
                end

                YELLOW: begin
                    currentState <= YELLOW;
                    if(lightTime == 5'd1) begin
                        light <= RED;
                        if(peak)
                            lightTime <= 5'd8;
                        else
                            lightTime <= 5'd16;
                        feedback <= 1'b1;
                    end
                    else
                        lightTime <= lightTime - 5'd1;
                end

                RED: begin
                    currentState <= RED;
                    if(lightTime == 5'd1) begin
                        light <= GREEN;
                        lightTime <= 5'd16;
                        feedback <= 1'b1;
                    end
                    else
                        lightTime <= lightTime - 5'd1;
                end
            endcase
        end
    end
endmodule