US 6,675,303 B1 · PC card controller with advanced power management reset capabilities

Abstract

A power management PC expansion card controller that includes power on reset circuitry to reset power management enable registers during a reset period, thereby ensuring that the PME registers correctly identify the power management capabilities of the controller. Once the PME registers are reset, an instruction may be provided to change the state of the registers from a default reset state to a state that supports advanced power management capabilities, for example wake-up functions. Additionally, the controller includes blocking circuitry to block conventional reset signals from resetting the power management and proprietary registers if the PME register is instructed to change states, thereby preserving the data contained in the power management and proprietary registers against future reset events. The controller of the present invention supports advanced power management specifications without requiring additional pinout arrangement or reassignment of pin functionality, so that the controller of the present invention can be implemented in current computer system without a the need for retooling or re-layout of system board circuitry and wiring diagrams.

Claims25

Dependent claims

A PC card controller, comprising:

power management event enable (PME) registers, said PME registers being reset to a default state and generating a control signal indicative of said default state, and said PMF registers adapted to receive instruction to change from a default state to a different state and generating a control signal indicative of said different state;
power management registers;
a trigger signal that changes state when power is first applied to said PME registers;
power on reset circuitry receiving said trigger signal and generating a first reset signal to reset said PME registers when said power is first applied to said PME registers, and generating a second reset signal to reset said power management registers when said power is first applied to said power management registers;
and
blocking circuitry receiving a conventional reset signal for said power management registers and said control signal and generating said second reset signal, wherein once said control signal indicates a different state, said blocking circuitry preventing said power management registers from being reset by said conventional reset signal.

3 more elements

Dependencies are inferred from the claim text.

PC card controller with advanced power management reset capabilities

Life of this patent

PC card controller with advanced power management reset capabilities

Life of this patent

Abstract

Claims25