In certain aspects of the disclosure, a chip includes an isolation device, wherein the isolation device is configured to allow a signal to pass from a first circuit in a first power domain to a second circuit in a second power domain via a signal line that crosses between the first and second power domains when the isolation device is disabled, and to clamp a portion of the signal line in the second power domain to a logic state when the isolation device is enabled. The chip also includes a failure detector configured to detect an imminent power failure of at least one of the first power domain or the second power domain, and to enable the isolation device in response to detection of the imminent power failure.