| (3) 多个波形元素的惯性延迟赋值语句的语义 同一语句中第一个波形元素之后的各波形元素不看作是惯性延迟。 例1: P1: process begin S <= 1 after 1 ns, 3 after 3 ns, 5 after 5 ns; end process; 信号赋值语句是惯性延迟,但后面两波形元素相对于第一个元素,按传输延迟处理(图2.15)。
例1不等价于例2: 例2: P1: process begin S <= 1 after 1 ns; S <= 3 after 3 ns; S <= 5 after 5 ns; end process; 根据惯性延迟的处理原则,前两个语句无效,相当于只有最后一个语句(图2.16)。
例1等价于例3(图2.17): 例3: P1: process begin S <= 1 after 1 ns; S <= transport 3 after 3 ns; S <= transport 5 after 5 ns; end process;
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