按键的使用方法（三）-------verilog

按键的使用方法三：一键三用： 点击、长击和双击、

代码：

    /********************************Copyright**************************************
001    **----------------------------File information--------------------------
002    ** File name  :key_function_3.v
003    ** CreateDate :2015.03
004    ** Funtions   :按键的用法（三）：一个按键完成单击，长击，双击的作用。
005    ** Operate on :M5C06N3L114C7
006    ** Copyright  :All rights reserved.
007    ** Version    :V1.0
008    **---------------------------Modify the file information----------------
009    ** Modified by   :
010    ** Modified data :
011    ** Modify Content:
012    *******************************************************************************/

     module  key_function_3 (
                                     clk,
                                     rst_n,

                                     key_6,

                                     led_S,
                               led_L,
                                     led_D

                                         );
     input          clk;
     input          rst_n;

     input          key_6;

     output         led_S;
     output         led_L;
     output         led_D;

    //--------------------------------------------
    /* 定时：100ms，2s */
      reg           count_en;
      localparam  t_1s = 'd23999999;
        localparam  t_100ms = 'd2399999;

    //  localparam  t_1s = 25'd2399;         /* //测试使用 */
    //    localparam  t_100ms = 22'd239;       /* //测试使用 */

      localparam  t_2s = 'd2;

        reg      [:]      count;
     always @(posedge clk or negedge rst_n)
     begin
      if(!rst_n)
       begin
            count <= ;
        end
      else if(count_en)
        begin
           if(count == t_1s)
                     count <= ;
                else
                    count <= count + ;
        end
       else
              count <= ;
      end

     reg     [:]   count1;
     always @(posedge clk or negedge rst_n)
     begin
      if(!rst_n)
       begin
           count1 <= ;
        end
      else if(count_en)
        begin
             if(count1 == t_2s)
                 count1 <= 'd2;
             else if(count == t_1s)
                  count1 <= count1 + ;
        end
       else
              count1 <= ;
      end

    //-------------------------------
     /* 取key_6的上升沿和下降沿   */
     reg    [:]    key_6_reg;
     wire            key_6_pos;
     wire            key_6_neg;
     always @(posedge clk or negedge rst_n)
     begin
      if(!rst_n)
       begin
           key_6_reg  <= 'b111;
        end
      else
        begin
           key_6_reg  <= {key_6_reg[:],key_6};
        end
      end
        assign  key_6_pos = (key_6_reg[:] == 'b01);
        assign  key_6_neg = (key_6_reg[:] == 'b10);

     //------------------------------
     /*  状态机 */
      reg   [:]   state;
      reg           key_S;
        reg           key_L;
        reg           key_D;
        always @(posedge clk or negedge rst_n)
         begin
          if(!rst_n)
           begin
               state <= 'd0;
                     count_en <= ;
                     key_S <= ;
                     key_L <= ;
                     key_D <= ;
            end
          else
            begin
              case(state)
                     'd0:
                        begin
                               count_en <= ;
                                 key_S  <= ;
                           key_L  <= ;
                                 key_D <= ;
                          if(key_6_neg)          /* 按键按下  */
                                  state <= 'd1;
                                else
                                    state <= 'd0;
                         end
                        'd1:
                          begin
                                if(key_6_pos)            /* 按键释放   */
                                    begin
                                          count_en  <= ;
                                            state <= 'd3;
                                        end
                                 else  if((key_6_reg == 'b000)&&(count1 == t_2s))     /* 按键长击   */
                                     begin
                                            count_en  <= ;
                                            state <= 'd2;
                                            key_L <= ;
                                            end
                                else
                                    count_en  <= ;
                            end
                         'd2:
                           begin
                                 key_L <= ;
                                 if(key_6_pos)
                                      state <= 'd7;
                                    else
                                        state <= 'd2;
                             end
                        'd3:
                              begin
                            state <= 'd4;
                                 end
                        'd4:                                                      /* 决定单击还是双击 */
                          begin
                                if((key_6_neg)&&((count1 == )&&(count < t_100ms)))       /* 双击 *//* 按键按下  */
                                  begin
                                         count_en  <= ;
                                         state <= 'd6;
                                         key_D <= ;
                                        end
                                 else if((count1 == )&&(count > t_100ms))             /* 单击 */
                                     begin
                                         count_en  <= ;
                                         state <= 'd5;
                                         key_S <= ;
                                     end
                                 else
                                   count_en  <= ;
                                end
                            'd5:
                              begin
                                    state <= 'd8;
                                    key_S <= ;
                                end
                            'd6:
                              begin
                                    key_D <= ;
                                    if(key_6_pos)                                     /* 按键释放 */
                                        state <= 'd8;
                                    else
                                        state <= 'd6;
                                    end
                            'd8:
                              begin
                                      state <= 'd0;
                                    end
                      default:state <= 'd0;
                    endcase

            end
          end

      reg  [:]    led;
        always @(posedge clk or negedge rst_n)
         begin
          if(!rst_n)
           begin
              led <= 'b000;
            end
          else
            begin
             if(key_S)
                      led[]<= ~led[];
                 else if(key_L)
                      led[]<= ~led[];
                 else if(key_D)
                      led[]<= ~led[];
            end
          end

    //------------------------------
    assign {led_D,led_L,led_S} = led;

    endmodule

难点：单击与双击的处理部分，状态机部分

测试代码

    /********************************Copyright**************************************
01    **----------------------------File information--------------------------
02    ** File name  :key_function_testbench.v
03    ** CreateDate :2015.03
04    ** Funtions   :按键功能的测试文件
05    ** Operate on :M5C06N3L114C7
06    ** Copyright  :All rights reserved.
07    ** Version    :V1.0
08    **---------------------------Modify the file information----------------
09    ** Modified by   :
10    ** Modified data :
11    ** Modify Content:
12    *******************************************************************************/
    `timescale  ns/ ns
    module  key_function_3_tb;
     reg          clk;
     reg          rst_n;

     reg          key_6;

     wire         led_S;
     wire         led_L;
     wire         led_D;

     key_function_3 key_function_3_1(
                                                 .clk,
                                                 .rst_n,

                                                 .key_6,

                                                 .led_S,
                                                 .led_L,
                                                 .led_D

                                                     );

    parameter  tck = ;
    parameter  t = /tck;

    always  #(t/)   clk = ~clk;

        initial
            begin
          clk = ;
                rst_n = ;
                key_6 = ;

              #(*t)  rst_n = ;

                #(*t);

                /* 点击 */
                #(*t)  key_6 = ;
              #(*t)   key_6 = ;
                #(*t)  key_6 = ;

                /* 长击 */
                #(*t);
                #(*t)   key_6 = ;
              #(*t)   key_6 = ;
                #(*t);
                #(*t)   key_6 = ;

                        /* 双击 */
                #(*t);
                #(*t)  key_6 = ;
              #(*t)  key_6 = ;
                #(*t)  key_6 = ;
              #(*t)  key_6 = ;
                #(*t)  key_6 = ;
        end

    endmodule

仿真波形

注：参考资料来自网络。