Specifications

Technical Reference Guide www.hp.com 4-15
System Support
4.6.2 GPIO Functions
SB700 Functions
The SB700 South Bridge provides various functions through the use of programmable general
purpose input/output (GPIO) ports. These systems use GPIO ports and associated registers of the
for the following functions:
■ Chassis and board ID
■ Front audio/USB detect
■ SPI data I/O
■ SATA hard drive LED
■ Flash security override
■ Serial port (COM 2) detect
SIO Controller Functions
In addition to the serial and parallel port functions, the SIO controller provides the following
specialized functions through GPIO ports:
■ Power/hard drive LED control for indicating system events (refer to Table 4-8)
■ Chassis and CPU fan control (PWM)
■ PCI Wake control
■ Power On/Power Good control
■ Power supply fan control