Compaq 850 manual 2 82801 ICH General Purpose Functions, 82801 ICH2 Gpio Register Utilization

Chapter 4 System Support

4.8.2 82801 ICH GENERAL PURPOSE FUNCTIONS

The 82801 ICH2 component includes a number of single and multi-purpose pins available as general-purpose input/output (GPIO) ports. The GPIO ports are configured (enabled/disabled) during POST by BIOS through the PCI configuration registers of the ICH’s LPC I/F Bridge (82801, function 0). The GPIO ports are controlled through 64 bytes of I/O space that is mapped during POST.

Table 4-15 lists the utilization of the ICH’s GPIO ports in the desktop and minitower systems.

Table 4-15.82801 ICH GPIO Register Utilization (Desktop and Minitower only)

Table 4-15.

82801 ICH2 GPIO Register Utilization

GPIO Port #	Function	Direction
0	PS LED	I
1	NIC REQ5	I
2	IRQE-	I
3	IRQF-	I
4	IRQG-	I
5	IRQH-	I
6	HD LED	I
7	--	NC
8		NC
12	TAFI ASIC Interrupt	I
13	SMI	I
18	--	NC
19	--	NC
20	--	NC
21	--	NC
22	--	NC
23	--	NC
24		NC
25	--	NC
26		NC
27		NC
28	Password Enable	I

NOTE:

NC = not connected (not used).

4-36Compaq Deskpro EXS and Workstation 300 Personal Computers Featuring the Intel Pentium 4 Processor

First Edition - December 2000