Maximum clock frequency of the circuit

Question

What do you mean by the term set up time and hold time constraints? Explain what do they mean? Which one is vital for estimating the maximum clock frequency of the circuit?

Answer 1

Set up time constraint means how late the input signal can arrive prior to the active edge of the flip-flop. Smaller the set up time, the better.

Hold time on the other hand means how long the value at the input requires to be held stable after the active edge.

Again the smaller the hold time, is the better.

For estimating the maximum clock frequency, set up time is much critical.