HP dc73 Technical Reference Guide: HP Compaq dc7800 Series Business Desktop Co - Page 54

I/O Controller Functions

Page 54 highlights

System Support ■ Chassis and board ID ■ Hood (cover) sensor and lock detect ■ Media card reader detect ■ S4 state indicator ■ USB port over-current detect ■ Flash security override ■ Serial port detect ■ REQn#/GNTn# sigal control ■ Password enable ■ Boot block enable I/O Controller Functions In addition to the serial and parallel port functions, the SCH5327 I/O controller provides the following specialized functions through GPIO ports: ■ Power/Hard drive LED control for indicating system events (refer to Table 4-8) ■ Hood lock/unlock controls the lock bar mechanism ■ Thermal shutdown control turns off the CPU when temperature reaches certain level ■ Processor present/speed detection detects if the processor has been removed. The occurrence of this event will, during the next boot sequence, initiate the speed selection routine for the processor. ■ Legacy/ACPI power button mode control uses 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. 4-16 www.hp.com Technical Reference Guide

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4-16
www.hp.com
Technical Reference Guide
System Support
Chassis and board ID
Hood (cover) sensor and lock detect
Media card reader detect
S4 state indicator
USB port over-current detect
Flash security override
Serial port detect
REQn#/GNTn# sigal control
Password enable
Boot block enable
I/O Controller Functions
In addition to the serial and parallel port functions, the SCH5327 I/O controller provides the
following specialized functions through GPIO ports:
Power/Hard drive LED control for indicating system events (refer to Table 4-8)
Hood lock/unlock controls the lock bar mechanism
Thermal shutdown control turns off the CPU when temperature reaches certain level
Processor present/speed detection detects if the processor has been removed. The occurrence
of this event will, during the next boot sequence, initiate the speed selection routine for the
processor.
Legacy/ACPI power button mode control uses 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.