用verilog写一个运动秒表，并用八段共阳极数码管显示数据

好的，下面是一个简单的Verilog代码实现：

module stopwatch(
    input clk, //时钟信号
    input reset, //复位信号
    output reg [3:0] seg, //8位7段数码管的输出
    output reg [2:0] dig //数码管的位选信号
);
 
reg [23:0] count; //计时器
reg [3:0] sec; //秒数
reg [3:0] msec; //毫秒数
 
always @(posedge clk or posedge reset) begin
    if (reset) begin
        count <= 0;
        sec <= 0;
        msec <= 0;
    end else begin
        count <= count + 1;
        if (count == 24000000) begin //时钟频率为24MHz
            count <= 0;
            msec <= msec + 1;
            if (msec == 10) begin
                msec <= 0;
                sec <= sec + 1;
                if (sec == 10) begin
                    sec <= 0;
                end
            end
        end
    end
end
 
always @(sec, msec) begin
    case ({sec, msec})
        8'b00000000: seg = 8'b11000000; //0
        8'b00000001: seg = 8'b11111001; //1
        8'b00000010: seg = 8'b10100100; //2
        8'b00000011: seg = 8'b10110000; //3
        8'b00000100: seg = 8'b10011001; //4
        8'b00000101: seg = 8'b10010010; //5
        8'b00000110: seg = 8'b10000010; //6
        8'b00000111: seg = 8'b11111000; //7
        8'b00001000: seg = 8'b10000000; //8
        8'b00001001: seg = 8'b10010000; //9
        default: seg = 8'b11111111; //空白
    endcase
end
 
always @(posedge clk) begin
    case (dig)
        3'b000: begin seg = seg; dig = 3'b001; end
        3'b001: begin seg = seg; dig = 3'b010; end
        3'b010: begin seg = seg; dig = 3'b011; end
        3'b011: begin seg = seg; dig = 3'b000; end
    endcase
end
 
endmodule

这个代码实现了一个简单的运动秒表，它使用一个时钟信号和一个复位信号来控制计时器的计数。计时器的精度为毫秒，当计时器达到1秒时，秒数加1，并且计时器归零。然后，使用一个case语句将秒数和毫秒数转换为相应的7段数码管输出。最后，使用一个case语句来控制数码管的位选信号，以便在每个时钟周期中更新数码管的输出。