System and method to set pme—status bit and wake up the system, and selectively load device driver by searching who set the bit without requiring clock

Abstract

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 (PME) 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.