Abstract: A technique of operating a processor subsystem masks interrupts to the processor subsystem during a power-down sequence of a processor of the processor subsystem. A boot vector for the processor of the processor subsystem is set. The boot vector provides an address associated with a saved processor state. A current state of the processor is saved to provide the saved processor state. The technique determines whether one or more first masked interrupts occurred during the saving of the current state of the processor. The processor that is to be powered-down is stopped when the one or more first masked interrupts did not occur during the saving of the current state of the processor. The technique also determines whether one or more second masked interrupts occurred following the saving of the current state of the processor. The processor is powered-down when the one or more second masked interrupts did not occur following the saving of the current state of the processor.

Abstract: A circuit device having data retention latches utilizes a test interface and system test controller to control one or more components of the circuit device to ensure proper conditions for testing the data retention latches. The data retention latches each include a scan component that is part of a scan chain, a first latching component that is powered in a first voltage domain and a second latching component that is powered in a second voltage domain, where one of the voltage domains can be effectively shut down when the circuit device is placed in a low-voltage mode. The system test controller can control a scan controller used to scan test data in and out of the scan chain. The system test controller further can control a power controller used to manage a power down sequence and a power up sequence so as to ensure that the data retention latches are not placed in spurious states.

Abstract: A circuit device having data retention latches utilizes a test interface and system test controller to control one or more components of the circuit device to ensure proper conditions for testing the data retention latches. The data retention latches each include a scan component that is part of a scan chain, a first latching component that is powered in a first voltage domain and a second latching component that is powered in a second voltage domain, where one of the voltage domains can be effectively shut down when the circuit device is placed in a low-voltage mode. The system test controller can control a scan controller used to scan test data in and out of the scan chain. The system test controller further can control a power controller used to manage a power down sequence and a power up sequence so as to ensure that the data retention latches are not placed in spurious states.