Time Response in Combinational Networks
• emphasis on timing behavior of circuits
• waveforms to visualize what is happening
• simulation to create these waveforms
• momentary change of signals at the outputs: hazards
can be useful— pulse shaping circuits
can be a problem — glitches: incorrect circuit operation
gate delay— time for change at input to cause change at output
minimum delay vs. typical/nominal delay vs. maximum delay
careful designers design for the worst case!
rise time— time for output to transition from low to high voltage
fall time— time for output to transition from high to low voltage