4 Summary of the HP/Phoenix BIOS

HP/Phoenix BIOS Description

Little Ben

Little Ben is an HP application specific integrated circuit (ASIC) that is connected between the chipset and the processor. It has been designed to act as a companion to the Super I/O chip. It contains the following:

•Hard and soft power control.

•BIOS timer:

hardware-wired, 50 ms long 80 Hz beep module;

automatic blinker that feeds the LEDs module with a 1 Hz oscillator signal.

•Flash access and protection (supporting 128, 256 or 512 ROMs).

•Super I/O protection.

•Glue logic:

Support for SMIs (for Intel’s SMM mode). Enhanced keyboard lock and external wake-up;

IRQ generator controlled by software; SMI generator controlled by software; Programmable chip selects.

•16-bit address decoding and remapping.

•Four general purpose I/O (Input/Output).

Little Ben is powered by battery, so its consumption has to be as low as possible. When VccState and PowerGood pins are both low, all output pins are in tri-state mode, except for RemoteOnBen which continues to be driven. This allows the PC to be restarted even after a power loss has occurred.

If the BIOS needs to turn off the PC, it must ensure that the PC is not locked by Little Ben’s lock bit. If it is, the power remains on, a red light is illuminated, and a buzzer is activated.

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