Patent ID: 8051313

Claim:
A method of asynchronously reducing power of a power domain, comprising: receiving a sleep command for said power domain; receiving, upon receiving said sleep command, an affirmative retention status signal denoting that a retention area in said power domain has stored data; receiving, upon receiving said sleep command, an affirmative isolation status signal that denotes that an isolation of said power domain has occurred; receiving, upon receiving said sleep command, an affirmative power status signal, denoting that a power is being applied to all of said power domain; and providing a power domain off command to said power domain upon receiving at least said sleep command, said affirmative status retention signal, said affirmative power status signal and said affirmative status isolation signal; wherein the method does not output said power domain off command when said sleep command, said affirmative power status signal, said affirmative retention status signal and said affirmative isolation status signal are not all received.