Advanced Configuration and Power Interface

hardware, standard (ACPI) An open industry standard

developed by Intel, Microsoft, and Toshiba for

configuration and power management.

The key element of the standard is power management with two

important improvements. First, it puts the OS in control of

power management. In the currently existing APM model most

of the power management tasks are run by the BIOS, with

limited intervention from the OS. In ACPI, the BIOS is

responsible for the dirty details of communicating with

hardware equipment but the control is in the OS.

The other important feature is bringing power management

features now available in portable computers only to the

desktop as well as into servers. Extremely low consumption

states, i.e., in which only memory, or not even memory is

powered, but from which ordinary interrupts (real time clock,

keyboard, modem, etc.) can quickly wake the system, are today

available in portables only. The standard should make these

available for a wider range of systems.

For ACPI to work the operating system, the motherboard

chipset, and for some functions even the CPU has to be

designed for it. Microsoft is heavily driving a move toward

ACPI, both Windows NT 5.0 and Windows 98 will support it.

It remains to be seen how much hardware manufacturers will

embrace the technology and whether other operating system

vendors will support it.

ACPI Information Page .

(1998-03-27)