regarding hvt and lvt cells

why hvt cell having high threshold value and lvt cells having low threshold value

HVT is High Voltage Threshold, LVT is Low Voltage Threshold.

See https://www.edaboard.com/threads/108768/ for details

venkatramanan,
hvt cells ll be used wher leakage power is the constraint. hvt cells ll have high delay and hence effects speed..
lvt cells are proffered when speed is the constraint in the design..

In layouts, some layers decide whether its a lvt or hvt..
In process identifying these layers vt ll decided..

Threshold voltage variation is obtained by varying channel dopping. High threshold voltage cell have less channel dopping while Low threshold voltage cells have high channel dopping. A library having multiple threshold voltage cells is called multi-vt library. Multi-VT library contains three VT flavors i.e. High Threshold Voltage (HVT) , Regular Threshold Voltage (RVT) , Low Threshold Voltage (LVT). High VT cells have less leakage power and also less driving capability. Low VT cells have high driving capability and also high leakage power. LVT cell are used in timing critical paths to meet timing requirement. HVT are used in non-timing critical paths to save power. So the purpose of having multi-VT library is to obtain high performance and low power designs.

https://www.edaboard.com/threads/219061/#2
https://www.edaboard.com/threads/219144/#3
https://www.edaboard.com/threads/230661/#5

thank u so much