Propagation Delay Calculations

STA calculates the delay along each timing path by determining the Gate delay and Net delay.

1. Gate Delay : Amount of delay from the input to the output of a logic gate. It is calculated based on 2 parameters.

---Input Transition Time 

---Output Load Capacitance

2. Net Delay : Amount of delay from the output of a gate to the input of the next gate in a timing path. It depends on the following parameters.

--Parasitic Capacitance.

--Resistance of net 

During STA, the tool calculates timing of the path by calculating:

1. Delay from input to output of the gate (Gate Delay).

2. Output Transition Time -> (which in turn depends on Input Transition Time and Output Load Capacitance)