Question

JK触发器代码：

计数器代码：

Class.cast

测试平台代码：

library ieee;
use ieee.std_logic_1164.all;

ENTITY JK IS PORT
(
    J,K,clk,rst,set : IN std_logic;
    Q, nQ : OUT std_logic
);
END JK;


ARCHITECTURE arch OF JK IS
    SIGNAL Qtemp : std_logic := '0';
    SIGNAL nQtemp : std_logic := '1';
BEGIN

    Q <= Qtemp;
    nQ <= nQtemp;

    jk_process : PROCESS(clk,rst,set)
    BEGIN
        if(rst = '1') then
            Qtemp <= '0';
            nQtemp <= '1';

        elsif(set = '1') then
            Qtemp <= '1';
            nQtemp <= '0';

        elsif(clk'event and clk = '1') then
            if(J = '0' and K = '0') then
                NULL;
            elsif(J = '1' and K = '0') then
                Qtemp <= '1';
                nQtemp <= '0';
            elsif(J = '0' and K = '1') then
                Qtemp <= '0';
                nQtemp <= '1';
            elsif(J = '1' and K = '1') then
                Qtemp <= not Qtemp;
                nQtemp <= not nQtemp;
            end if;
        end if;
    END PROCESS;
END arch;

以上代码的波形：

在所有JK触发器上的rst <='0'时的波形：

我有两个无法解决的问题：

在第一个时钟脉冲之前，Q和nQ中的值不同于0000。我不知道这些值的来源。
主要问题：当B3B2B1B0为1010时，需要重置整个计数器，但计数器永远不会达到该状态。取而代之的是，当计数器处于状态1001且不会为1时，它不应重置该计数器的状态。

有趣的是，当我在所有JK触发器上将0强制设为rst输入时，and开始正常工作，并且library ieee; use ieee.std_logic_1164.all; ENTITY brojilo IS PORT ( clk : IN std_logic; Q_vector : OUT std_logic_vector(3 downto 0) := "0000"; Q_negated_vector : OUT std_logic_vector(3 downto 0) := "0000"; and_in_values : OUT std_logic_vector(3 downto 0) := "0000"; and_out_value : OUT std_logic := '0' ); END brojilo; ARCHITECTURE arch OF brojilo IS SIGNAL int_clk_b0_b1 : std_logic := '0'; SIGNAL int_clk_b1_b2 : std_logic := '0'; SIGNAL int_clk_b2_b3 : std_logic := '0'; SIGNAL Q_temp_vector : std_logic_vector(3 downto 0) := "0000"; SIGNAL Q_temp_negated_vector : std_logic_vector(3 downto 0) := "0000"; SIGNAL and_vector : std_logic_vector(3 downto 0) := "0000"; SIGNAL and_out_reset : std_logic := '0'; BEGIN and_out_reset <= and_vector(0) and and_vector(1) and and_vector(2) and and_vector(3); and_out_value <= and_out_reset; b0 : ENTITY work.JK port map(J => '1', K => '1', clk => clk, rst => and_out_reset, set => '0', Q => Q_temp_vector(0), nQ => Q_temp_negated_vector(0)); int_clk_b0_b1 <= Q_temp_negated_vector(0); b1 : ENTITY work.JK port map(J => '1', K => '1', clk => int_clk_b0_b1, rst => and_out_reset, set => '0', Q => Q_temp_vector(1), nQ => Q_temp_negated_vector(1)); int_clk_b1_b2 <= Q_temp_negated_vector(1); b2 : ENTITY work.JK port map(J => '1', K => '1', clk => int_clk_b1_b2, rst => and_out_reset, set => '0', Q => Q_temp_vector(2), nQ => Q_temp_negated_vector(2)); int_clk_b2_b3 <= Q_temp_negated_vector(2); b3 : ENTITY work.JK port map(J => '1', K => '1', clk => int_clk_b2_b3, rst => and_out_reset, set => '0', Q => Q_temp_vector(3), nQ => Q_temp_negated_vector(3)); and_vector(0) <= Q_temp_negated_vector(0); and_vector(1) <= Q_temp_vector(1); and_vector(2) <= Q_temp_negated_vector(2); and_vector(3) <= Q_temp_vector(3); and_in_values <= and_vector; Q_vector <= Q_temp_vector; Q_negated_vector <= Q_temp_negated_vector; END arch;输出行在1010上触发1。

JK 4位向上计数器-1010上的复位不起作用

0 个答案: