解决方法:使用“异或”(xor)逻辑。示例如下: process (CLK) begin if rising_edge(CLK) then SIG_RISE_OUT <= SIG_FALL_OUT xor D_IN0; end if; end process; process (CLK) begin if falling_edge(CLK) then SIG_FALL_OUT <= SIG_RISE_OUT xor D_IN1; end if; end process; D_OUT <= SIG_RISE_OUT xor SIG_FALL_OUT;