FPGA驱动us100超声波模块的verilog代码

下面是一个基本的Verilog代码示例，可用于驱动US-100超声波模块：

module us100(
    input clk,
    input reset,
    output reg trig,
    input echo,
    output reg [11:0] distance
    );

    reg [7:0] count;
    reg [7:0] timeout;
    reg [7:0] delay;
    reg [11:0] pulse_width;
    reg [11:0] temp_distance;
    reg [1:0] state;

    parameter IDLE = 2'd0;
    parameter SEND_PULSE = 2'd1;
    parameter WAIT_ECHO = 2'd2;

    always @(posedge clk) begin
        if (reset) begin
            trig <= 0;
            count <= 0;
            timeout <= 0;
            delay <= 0;
            pulse_width <= 0;
            temp_distance <= 0;
            state <= IDLE;
            distance <= 0;
        end
        else begin
            case (state)
                IDLE: begin
                    count <= 0;
                    timeout <= 0;
                    delay <= 0;
                    pulse_width <= 0;
                    temp_distance <= 0;
                    trig <= 0;
                    if (echo) begin
                        state <= WAIT_ECHO;
                    end
                    else begin
                        state <= SEND_PULSE;
                    end
                end
                SEND_PULSE: begin
                    count <= count + 1;
                    if (count >= 12) begin
                        count <= 0;
                        pulse_width <= 0;
                        delay <= 0;
                        trig <= 1;
                        state <= WAIT_ECHO;
                    end
                end
                WAIT_ECHO: begin
                    if (echo) begin
                        pulse_width <= pulse_width + 1;
                        timeout <= 0;
                    end
                    else begin
                        if (pulse_width > 0) begin
                            temp_distance <= pulse_width * 10 / 58;
                            distance <= temp_distance;
                        end
                        state <= IDLE;
                    end
                    if (pulse_width >= 600) begin
                        pulse_width <= 0;
                        state <= IDLE;
                    end
                    else if (timeout >= 80) begin
                        pulse_width <= 0;
                        state <= IDLE;
                    end
                    else begin
                        timeout <= timeout + 1;
                    end
                end
            endcase
        end
    end
endmodule

这个Verilog代码实现了一个简单的状态机，用于控制US-100超声波模块的操作。在初始状态下，模块处于IDLE状态，等待Echo引脚的高电平触发。当Echo引脚为低电平时，模块开始发送超声波信号，进入SEND_PULSE状态。当发送完超声波信号后，模块进入WAIT_ECHO状态，等待Echo引脚的响应信号。如果Echo引脚在规定的时间内没有响应，模块将返回IDLE状态。如果Echo引脚响应了信号，模块将根据返回的信号宽度计算距离，并返回IDLE状态。在这个过程中，模块会根据需要生成一些延迟和计时信号，以控制超声波信号的发送和接收。