Loading... ### 同步复位 只有当“时钟沿”到来时，才能完成复位。 ### 异步复位 无论“时钟沿”是否到来，只要复位信号到来，就完成复位。 ### Example 以D触发器为例来说明同步复位和异步复位的区别。 - code ```VHDL library IEEE; use IEEE.STD_LOGIC_1164.ALL; ENTITY Reset IS PORT( clock, clear, d : IN STD_LOGIC; q : OUT STD_LOGIC ); END ENTITY Reset; ARCHITECTURE one of Reset IS -- 同步复位 BEGIN PROCESS(clock, clear) BEGIN IF clock'EVENT AND clock = '1' THEN IF clear = '0' THEN q <= '0'; ELSE q <= d; END IF; END IF; END PROCESS; END ARCHITECTURE one; ARCHITECTURE two of Reset IS -- 异步复位 BEGIN PROCESS(clock, clear) BEGIN IF clear = '0' THEN q <= '0'; ELSIF clock'EVENT AND clock = '1' THEN q <= d; END IF; END PROCESS; END ARCHITECTURE two; CONFIGURATION do of Reset IS FOR two END FOR; END CONFIGURATION do; ``` - 波形仿真图   仔细对比同步复位和异步复位的波形仿真图即可理解，不过多赘述。 Last modification：June 28th, 2020 at 11:25 am © 允许规范转载