同步清零LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; ENTITY Dchu IS PORT (CLK,D:IN STD_LOGIC; Q:OUT STD_LOGIC; SCLK:IN STD_LOGIC); END; ARCHITECTURE FFQ OF Dchu IS SIGNAL Q1:STD_LOGIC; BEGIN PROCESS (SCLK,CLK,Q1) BEGIN IF CLK'EVENT AND CLK='1' THEN IF SCLK='1' THEN Q1<='0'; ELSE Q1<=D; END IF; END IF; END PROCESS; Q<=Q1; END FFQ; 异步置位apre LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; ENTITY Dchu IS PORT ( CLK : IN STD_LOGIC; D : IN STD_LOGIC; Q :OUT STD_LOGIC; APRE :IN STD_LOGIC ); E ND; ARCHITECTURE FFQ OF Dchu IS SIGNAL Q1:STD_LOGIC; BEGIN PROCESS (APRE,CLK,Q1) BEGIN IF APRE='1' THEN Q1<='1'; ELSIF CLK'EVENT AND CLK='1' THEN Q1<=D; END IF; END PROCESS; Q<=Q1; END FFQ; |
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