Semi-Modularity and
Computation Interference
18/3/2014
CE-653 - Hazards and Analysis
Methods
38
}Semi-modularity is a key property for designing hazard-free asynchronous
systems
}Definition [Semi-Modularity]
}a circuit is semi-modular, iff an output
transition which has been enabled to fire (by an
input transition) CANNOT subsequently be disabled (by a
subsequent input transition)
}Semi-modularity forces output acknowledgement
}InputàOutputànext Inputà …
}Thus leading to hazard-free SI systems
}Computation Interference
}Violation of Semi-modularity
}Example: AND2 gate with 11 inputs should present ^
rise transition before v in inputs