in general , a system and method for providing pci power management support without requiring a clock is disclosed . a computer is allowed to reside in a sleep mode and receive a power management event signal from an attached peripheral device in response to an external action request from an external source , thereby waking the computer and initializing device drivers to allow the peripheral device to perform predefined functions . during initiation of the power management system , the system provides a peripheral device with a pme_status bit . in response to an external event , the peripheral device receives an external action request from the source of the external event . the peripheral device then sets the pme_status bit and transmits a power management event signal to a computer operating system . upon receiving the pme signal , the computer turns back on . the computer operating system then searches all peripheral devices connected to the computer for the set pme_status bit . upon finding the source of the pme_status bit , the computer initializes a device driver , which is related to the peripheral device , thereby allowing the peripheral device to function accordingly and accommodate the external action request .