Synchronization failure

small, but non-zero probability that the FF output will get stuck in an in-between state

oscilloscope traces demonstrating

synchronizer failure and eventual

decay to steady state

logic 0

logic 1

logic 0

logic 1

• Occurs when FF input changes close to clock edge

  • the FF may enter a metastable state – neither a logic 0 nor 1 –
  • it may stay in this state an indefinite amount of time
  • this is not likely in practice but has some probability

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