Compaq W4000 User Manual

Page 87

Technical Reference Guide

Compaq Evo and Workstation Personal Computers

Featuring the Intel Pentium 4 Processor

Second Edition - January 2003

4-33

The systems covered in this guide utilize the following specialized functions built into the LPC
47B367 I/O Controller:

♦ Power/Hard drive LED control – The I/O controller provides color and blink control for the

front panel LEDs used for indicating system events as listed below:

System Status

Power LED

HD LED

S0: System on (normal operation)

Steady green

Green w/HD activity

S1: Suspend

Blinks green @ 1 Hz

Off

S3: Suspend to RAM

Blinks green @ 1 Hz

Off

S4: Suspend to disk

Blinks green @ 0.5 Hz

Off

S5: Soft off

Off - clear

Off

Processor not seated

Steady red

Off

CPU thermal shutdown

Off (system powers down)

ROM error

Blinks red @ 1 Hz

Off

Power supply crowbar activated

Blinks red @ 0.5 Hz

Off

System off

Off

NOTE:

[1] Later systems using PCA#s 011305, 011308, or 011311 will power down for this condition.

♦ Intruder sensing – Used on Small Form Factor and Desktop models, battery-backed D-latch

logic internal to the LPC47B367 is connected to the hood sensor switch to record hood
(cover) removal.

♦ Hood lock/unlock – Used on Small Form Factor and Desktop models, logic internal to the

LPC47B34x controls the lock bar mechanism.

♦ I/O security – The parallel, serial, and diskette interfaces may be disabled individually by

software and the LPC47B367’s disabling register locked. If the disabling register is locked, a
system reset through a cold boot is required to gain access to the disabling (Device Disable)
register.

♦ Processor present/speed detection – One of the battery-back general-purpose inputs (GPI26)

of the LPC47B367 detects if the processor has been removed. The occurrence of this event is
passed to the ICH2 that will, during the next boot sequence, initiate the speed selection
routine for the processor. The speed selection function replaces the manual DIP switch
configuration procedure required on previous systems.

♦ Legacy/ACPI power button mode control – The LPC47B367 receives the pulse signal from

the system’s power button and produces the PS On signal according to the mode (legacy or
ACPI) selected. Refer to chapter 7 for more information regarding power management.