verilog hdl这段代码实在不知道怎么修改了
module trafficlighte(
input clk, // 时钟
input emergency_btn // 紧急事件按钮
);
// 信号定义
reg [1:0] state; // 交通灯状态机状态
reg [5:0] counter; // 计数器
wire red_eastwest; // 东西方向红灯
wire yellow_eastwest; // 东西方向黄灯
wire green_eastwest; // 东西方向绿灯
wire red_northsouth; // 南北方向红灯
wire yellow_northsouth; // 南北方向黄灯
wire green_northsouth; // 南北方向绿灯
// 控制状态机
always @(posedge clk) begin
case (state)
2'b00: begin // 初始状态
counter <= 0;
red_eastwest <= 1;
green_northsouth <= 1;
state <= 2'b01;
end
2'b01: begin // 东西方向绿灯
if (counter >= 35) begin
counter <= 0;
yellow_eastwest <= 1;
green_eastwest <= 0;
state <= 2'b10;
end
end
2'b10: begin // 东西方向黄灯
if (counter >= 5) begin
counter <= 0;
red_eastwest <= 1;
yellow_eastwest <= 0;
state <= 2'b11;
end
end
2'b11: begin // 南北方向绿灯
if (counter >= 50) begin
counter <= 0;
yellow_northsouth <= 1;
green_northsouth <= 0;
state <= 2'b00;
end
end
endcase
// 判断紧急事件按钮状态
if (emergency_btn == 1) begin
state <= 2'b100;
end else if (state == 4'b1000) begin
state <= 2'b00;
end
counter <= counter + 1; // 计数器自增
end
// 端口实例化
assign eastwest_traffic_lights eastwest_lights(
.red(red_eastwest),
.yellow(yellow_eastwest),
.green(green_eastwest)
);
assign northsouth_traffic_lights northsouth_lights(
.red(red_northsouth),
.yellow(yellow_northsouth),
.green(green_northsouth)
);
endmodule