Re: Replacement of the Low-Vt cells with Hi-Vt cells on the critical paths -> How-to
LVT - faster cells, high power
HVT - slow cells, less power
Strange... the vendor told you that. :-D
I would suggest to have a single execution with both the libcells available and use the following attributes
--
max_leakage_power
power_optimization_effort
--
This should help you with a good leakage power saving. Also there was a time when the flow that you suggest i.e. two pass flow was used where mapping was executed with HVT and then during IOPT only was the LVT cells opened. So the paths that met timing did not use more of leaky cells i.e. LVT but only the paths that violated timing.
Although from my experience off late such a flow is not required and it does a good job using the above settings itself.