EEPW论坛

1) 数码管静态显示、动态显示及模为60的计数器显示效果如下：



2) 模为60的计数器，功能实现代码如下：
module modulo_60(sys_clk, sys_rstn, sm_seg, sm_bit);
 
//输入输出信号
    input sys_clk;
    input sys_rstn;
    output [7:0] sm_seg;
    output [7:0] sm_bit;
//寄存器定义
    reg [7:0] sm_seg;
    reg [7:0] sm_bit;
    reg [3:0] tens;  //十位数
    reg [3:0] units;  //个位数
    reg [3:0] dataout_buf;
    reg [31:0] scan_cnt;  //扫描延时计数器
    reg [31:0] delay_cnt;  //延时计数器
    reg disp_dat;
//逻辑部分
    always @(posedge sys_clk or negedge sys_rstn)//动态扫描延时
        begin
            if(!sys_rstn)
                scan_cnt <= 32'd0;
            else
                begin
                    if(scan_cnt==32'd49999)
                        scan_cnt <= 32'd0;
                    else
                        scan_cnt <= scan_cnt + 1'b1;
                end
        end
    always @(posedge sys_clk or negedge sys_rstn)//模计数延时
        begin
            if(!sys_rstn)
                delay_cnt <= 32'd0;
            else
                begin
                    if(delay_cnt==32'd49999999)
                        delay_cnt <= 32'd0;
                    else
                        delay_cnt <= delay_cnt + 1'd1;
                end
        end
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                disp_dat <= 1'b0;
            else
                begin
                    if(scan_cnt==32'd49999)
                        disp_dat <= disp_dat + 1'b1;
                    else
                        disp_dat <= disp_dat;
                end
        end
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                begin
                    units = 4'h0;
                    tens = 4'h0;
                end
            else
                begin
                    if(delay_cnt==32'd49999999)
                        begin
                            units = units + 1'b1;
                            if(units==4'ha)
                                begin
                                    units = 4'h0;
                                    tens = tens + 1'b1;
                                    if(tens==4'h6)
                                        tens = 4'h0;
                                end
                        end
                    else
                        begin
                            units = units;
                            tens = tens;
                        end
                end
        end   
    always @(disp_dat)
        begin
            case(disp_dat)
                1'b0: sm_bit = 8'b1111_1110;
                1'b1: sm_bit = 8'b1111_1101;
                default:
                        sm_bit = 8'b1111_1110;
            endcase
        end
    always @(sm_bit)
        begin
            case(sm_bit)
                8'b1111_1110: dataout_buf = units;
                8'b1111_1101: dataout_buf = tens;
                default:dataout_buf = 4'ha;
            endcase
        end
    always @(dataout_buf)
        begin
            case(dataout_buf)
                4'h0: sm_seg = 8'hc0;
                4'h1: sm_seg = 8'hf9;
                4'h2: sm_seg = 8'ha4;
                4'h3: sm_seg = 8'hb0;
                4'h4: sm_seg = 8'h99;
                4'h5: sm_seg = 8'h92;
                4'h6: sm_seg = 8'h82;
                4'h7: sm_seg = 8'hf8;
                4'h8: sm_seg = 8'h80;
                4'h9: sm_seg = 8'h90;
                4'ha: sm_seg = 8'h88;
                default:
                        sm_seg = 8'hc0;
            endcase
        end 
endmodule

5.8课后作业
按键消抖控制1位数码管循环显示0-9，代码如下：
module key_dt(sys_clk,
                  sys_rstn,
                  key_in,
                  sm_seg,
                  sm_bit);
                 
    input sys_clk;
    input sys_rstn;
    input key_in;
    output [7:0] sm_seg;  //段码
    output [7:0] sm_bit;  //位码
   
    reg [7:0] sm_seg;
    wire [7:0] sm_bit;
    reg [3:0] disp_dat;  //显示数据寄存器
    reg [19:0] delay_cnt;
    wire key_scan;
    wire key_low;
    reg key_samp;
    reg key_samp_r;
    reg key_rst;
    reg key_rst_r;
//按键脉冲边沿检测
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                key_samp <= 1'b1;
            else
                key_samp <= key_in;
        end
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                key_samp_r <= 1'b1;
            else
                key_samp_r <= key_samp;
        end
    assign key_scan = key_samp_r & (~key_samp);
//20ms延时，再次检测
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                delay_cnt <= 20'h0;
            else if(key_scan)
                delay_cnt <= 20'h0;
            else
                delay_cnt <= delay_cnt + 1'b1;
        end
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                key_rst <= 1'b1;
            else if(delay_cnt==20'hfffff)
                key_rst <= key_in;
        end
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                key_rst_r <= 1'b1;
            else
                key_rst_r <= key_rst;
        end
    assign key_low = key_rst_r & (~key_rst);
//按键控制1位数码管循环显示0-9
    always @(posedge sys_clk or negedge sys_rstn)
        begin
            if(!sys_rstn)
                disp_dat <= 4'd0;
            else if(key_low)
                begin
                    disp_dat <= disp_dat + 1'b1;
                    if(disp_dat==4'h9)
                        disp_dat <= 4'd0;
                end
            else
                disp_dat <= disp_dat;
        end
    always @(disp_dat)
        begin
            case(disp_dat)
                4'h0: sm_seg = 8'hc0;
                4'h1: sm_seg = 8'hf9;
                4'h2: sm_seg = 8'ha4;
                4'h3: sm_seg = 8'hb0;
                4'h4: sm_seg = 8'h99;
                4'h5: sm_seg = 8'h92;
                4'h6: sm_seg = 8'h82;
                4'h7: sm_seg = 8'hf8;
                4'h8: sm_seg = 8'h80;
                4'h9: sm_seg = 8'h90;
            endcase
        end
    assign sm_bit = 8'b0111_1111;
       
endmodule