Time Response in Combinational Networks

Detecting Static Hazards in Multi-Level Circuits

Calculate transient output function

variables and complements are treated as independent variables

cannot use X + X' = 1 or X • X' = 0 for simplifications

F = A B C + (A + D) (A' + C')

F1 = A B C + A A' + A C' + A' D + C' D

Example:

2-level form

ABCD: 1111 to 1110, covered by term

ABC, so no 1-hazard present

ABCD: 1110 to 1100, term ABC goes low

while term AC' goes high

some static hazards are present!

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