HP Deskpro EX Technical Reference Manual page 94

Chapter 4 System Support
4.9.3.2 I/O Controller Miscellaneous Functions
The systems covered in this guide utilize the following specialized functions built into the LPC
47B357 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
S0: System on (normal operation)
S1: Suspend
S3: Suspend to RAM
S4: Suspend to disk
S5: Soft off
Backplane board not seated
Processor not seated
CPU thermal shutdown
ROM error
Power supply crowbar activated
System off
NOTE:
[1] Minitower only. Desktop LED will be Off – clear.
I/O security – The parallel, serial, and diskette interfaces may be disabled individually by
software and the LPC47B357'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 LPC47B357 detects if the processor has been removed. The occurrence of this event is
passed to the ICH 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 LPC47B357 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.
4-42 Compaq Deskpro EX Series of Personal Computers
Power LED
Steady green
Blinks green @ 1 Hz
Blinks green @ 1 Hz
Blinks green @ 0.5 Hz
Off - clear
Steady red [1]
Steady red [1]
Blinks red @ 4 Hz [1]
Blinks red @ 1 Hz [1]
Blinks red @ 0.5 Hz [1]
Off
First Edition - August 2000
HD LED
Green w/HD activity
Off
Off
Off
Off
Steady red [1]
Off
Off
Off
Off
Off