Apple Inc.
Power down detection for non-destructive isolation signal generation

Abstract:

A power detection circuit for detecting powering down of a voltage domain in an integrated circuit is disclosed. The power detection circuit is placed in or near the voltage domain in the integrated circuit to provide power detection on the integrated circuit. The power detection circuit detects powering down of the voltage domain to provide an isolation enable signal to another voltage domain that interfaces with the powering down voltage domain. The isolation enable signal may be used by an isolation cell coupled to the non-powering down voltage domain to prevent corrupted logic being received from the powering down voltage domain.