Additional Hazards in Sequential Circuits
CE-653 - Hazards and Analysis
Methods
17
}Critical Race
}If order of changes in
state variables affects final state, race is critical
}11 à 10 à 00, or, 11à 01 à 00
}Essential Hazard
}Critical race between
input and feedback change – must add delay to fix
}Property of FSM specification
}Essential Hazard Detection:
}for input vector AàB,
}If single change (A, B) produces
different states and output to three change times (AàB, A, B) circuit contains
an
Essential Hazard
Essential Hazard
18/3/2014