L1 Register Programming

The following registers contain information about the L1 state:

  • Entering L1—The Low Power Debug and Control Register 0's L1 Entry Mode field in the local management space gives information about the last L1 entry mode. You can determine whether PM or ASPM was used to enter L1. This field is reset before each L1 entry operation.
  • Exit trigger for L1 (or L1 substate)—The Low Power Debug and Control Register 0's L1, L1.x Exit Reason field in the local management space gives information about the last L1 or L1 substate exit triggers. This field is reset before each L1 entry operation.