问题
IEEE Std 1800™-2012 section 4.9.5 says "Switch processing shall consider all the devices in a bidirectional switch-connected net before it can determine the appropriate value for any node on the net because the inputs and outputs interact. A simulator can do this using a relaxation technique."
What is this relaxation technique the LRM is referring to? Where can I read the detailed relaxation algorithm?
回答1:
A bidirectional switch is inherently an analog device. Trying to simulate this kind of device in a discrete event based digital simulator creates quite a challenge. This device can create many event feedback loops and the relaxation algorithm is there to prevent endless zero-delay loops of evaluation. The standard does not specify the actual implementation of this algorithm, but most simulators use ones derived from this paper by Randy Bryant.
来源：https://stackoverflow.com/questions/55981699/what-is-relaxation-technique-of-sv-tran-gates