>> "Synchronize all external wire inputs with two clocks before using them." This is why you need to sync external (async) inputs: "Metastability in electroni

>> "Synchronize all external wire inputs with two clocks before using them." This is why you need to sync external (async) inputs: "Metastability in electronics is the ability of a digital electronics system to persist for an unbounded time in an unstable equilibrium or metastable state. In metastable states, the circuit may be unable to settle into a stable '0' or '1' logic level within the time required for proper circuit operation. As a result, the circuit can act in unpredictable ways, and may lead to a system failure..." https://en.wikipedia.org/wiki/Metastability_in_electronics