Time Response in Combinational Networks
Hazards/Glitches and How to Avoid Them
Unwanting switching at the outputs
Occur because delay paths through the circuit experience
different propagation delays
Danger if logic "makes a decision" while output is unstable
OR hazard output controls an asynchronous input (these
respond immediately to changes rather than waiting for a
synchronizing signal called a clock)
wait until signals are stable (by using a clock)
never, never, never use circuits with asynchronous inputs
design hazard-free circuits
Suggest that first two approaches be used, but we'll tell you about
hazard-free design anyway!