Difference between PrimeTime and NanoTime? What is transistor-level STA

[gangnam_style]

How is Transistor level STA using NanoTime different from the regular STA performed using PrimeTime? What is the need for it?

 

[artmalik]

Nanotime is able to analyze a trasnsistor level netlist while primetime uses precharacterized timing .libs to analyze the timing. Suppose you custom circuit (transistor level ) with multiple transistor level flops. Nanotime will understand the topology of the design along with design using the spice models and analyse the constraints. Nanotime is an IP level tool while PT is a block level tool. Nanotime uses spice models to analyse the design and create .libs for the cell which is further used by the PT.