ACTIVE POWER DOWN FOR PC CARD I/O APPLICATIONS

摘要

A system for controlling the power consumption of an add-in PC card (10) operating within a host computer. The host computer includes a power supply (24) that provides all power used by the PC card (10 ). The PC card includes communication registers required for communication between the host computer and the PC card. The PC card als o includes a microcontroller (26) connected to an I/O subsystem (32) and a multi-pin I/O connector (36). A first side of multi-pin I/O connector (36) is connected to the I/O subsystem and second side (38) is connected to a source of I/O signals external to the hos t computer. An external register module (16) is connected to the microcontroller (26) and communicates with the host computer. The external register module (16) contains the communication registers. A status detector located on the PC card (10) detects whether the I/O subsystem (32) is processing I/O information, and supplies a status signal indicative thereof. A power management module (68) is also located on the PC card (10) and is connected to the status connector. The power management module receives the status signal from the status detector and supplies one or more predetermined power levels as a result of the status signal.