Patent ID: 6952113

Claim:
An integrated circuit (IC) comprising: a plurality of functional units selectively communicating with each other; a plurality of logic circuits connected together in ones of said plurality of functional units, connected said logic circuits in each of said ones defining function therein; selectable supply switching devices disposed at ones of said logic circuits selectively supplying power and alternately isolating connected said logic circuits, said selectable supply switching devices turning on at a threshold voltage having a magnitude greater than like devices in said logic circuits, wherein said devices are field effect transistors(FETs), ones of said selectable supply switching devices are p-type FETs (PFETs) connected between a supply line (V dd ) and an intermediate supply line; a decoupling capacitor at each said intermediate supply line; and a switchable bias supply at each selectable supply switching device selectively reducing threshold voltage magnitude responsive to said each selectable supply switching device supplying power.