JK触发器

JK触发器具有保持，置0，置1和翻转四个功能。

则可得出次态方程：\(Q_{n+1} = JQ_n'+K'Q_n\)

Design

`timescale 1ns / 1ps

module jk(clk,Reset,Set,J,K,Q);

input clk;

input Reset;

input Set;

input J;

input K;

output Q;

reg q;

always@(posedge clk)

    if(!Reset)

        begin

            q <= 1'b0;

        end

    else if(!Set)

        begin

            q <= 1'b1;

        end

    else

        begin

            case({J,K})

                2'b00 : q <= q;

                2'b01 : q <= 0;

                2'b10 : q <= 1;

                default : q <= ~q;

            endcase

         end

     assign Q=q;

endmodule

Simulation

`timescale 1ns / 1ps

module JK_sim();

reg Reset, Set, clk;

wire Q;

reg J, K;

jk uu(clk, Reset, Set, J, K, Q);

initial

    begin

    Reset = 0;

    Set = 0;

    clk = 1;

    J = 0;

    K = 0;

    #40 Reset = 1;

    #40 Set = 1;

    end

always #20{J, K} = {J, K} + 1;

always #10 clk = ~clk;

endmodule

波形图

模12计数器

需要使用4个JK触发器，卡诺图化简后得到触发器控制函数的最简与或式如下：

\(J_1 = K_1 = 1\)

\(J_2 = K_2 = Y_1^{n}\)

\(J_3 = (Y_4^n)'Y_2^nY_1^n\)

\(K_3 = Y_2^nY_1^n\)

\(J_4 = Y_3^nY_2^nY_1^n\)

\(K_4=Y_2^nY_1^n\)

Design

`timescale 1ns / 1ps

module count(Reset,Set,clk,Y);

input Reset;

input Set;

input clk;

output [3:0]Y;

wire j1,j2,j3,j4,k1,k2,k3,k4;

assign j1 = 1;

assign k1 = 1;

assign j2 = Y[0];

assign k2 = Y[0];

assign j3 = (~Y[3])&Y[1]&Y[0];

assign k3 = Y[0]&Y[1];

assign j4 = Y[0]&Y[1]&Y[2];

assign k4 = Y[0]&Y[1];

jk_0 u1 (clk,Reset,Set,j1,k1,Y[0]);

jk_0 u2 (clk,Reset,Set,j2,k2,Y[1]);

jk_0 u3 (clk,Reset,Set,j3,k3,Y[2]);

jk_0 u4 (clk,Reset,Set,j4,k4,Y[3]);

endmodule

Simulation

`timescale 1ns / 1ps

module sim_dev1();

reg Reset,Set,clk;

wire [3:0]Y;

initial

    begin

        Reset = 0;

        Set = 0;

        clk = 1;

        #20 Reset = 1;

        #20 Set = 1;

    end

always#20 clk = ~clk;

CNT12 u(Reset,Set,clk,Y);

endmodule