82801DB Datasheet, PDF (51/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Signal Description
2.18 General Purpose I/O
Table 2-18. General Purpose I/O Signals
Name
GPIO[47:44]
GPIO[43:38]
GPIO[37:32]
GPIO[31:29]
GPIO[28:27]
GPIO[26]
GPIO[25]
GPIO[24]
GPIO[23]
GPIO[22]
GPIO[21]
GPIO[20]
GPIO[19]
GPIO[18]
GPIO[17:16]
GPIO[15:14]
GPIO[13:12]
GPIO[11]
GPIO[10:9]
GPIO[8]
GPIO[7]
GPIO[6]
GPIO[5:2]
GPIO[1:0]
Type
I/O
I/O
I/O
O
I/O
I/O
I/O
I/O
O
OD
O
O
O
O
O
I
I
I
I
I
I
I
I
I
Description
Not implemented.
Can be input or output. Main power well.
Can be input or output. Main power well.
Not implemented.
Can be input or output. Resume power well. Unmuxed.
Not implemented.
Can be input or output. Resume power well. Unmuxed.
Can be input or output. Resume power well.
Fixed as output only. Main power well.
Fixed as output only. Main power well.
Fixed as output only. Main power well.
Fixed as output only. Main power well.
Fixed as output only. Main power well.
Fixed as output only. Main power well.
Fixed as Output only. Main power well. Can be used instead as PC/PCI
GNT[A:B]#. GPIO[17] can also alternatively be used for PCI GNT[5]#.
Integrated pull-up resistor.
Not implemented.
Fixed as Input only. Resume power well. Unmuxed.
Fixed as Input only. Resume power well. Can be used instead as SMBALERT#.
Not implemented.
Fixed as Input only. Resume power well. Unmuxed.
Fixed as Input only. Main power well. Unmuxed.
Fixed as Input only. Main power well.
Fixed as Input only. Main power well. Can be used instead as PIRQ[E:H]#.
Fixed as Input only. Main power well. Can be used instead as PC/PCI
REQ[A:B]#. GPIO[1] can also alternatively be used for PCI REQ[5]#.
NOTE: Main power well GPIO will be 5 V tolerant, except for GPIO[43:32]. Resume power well GPIO are not
5 V tolerant.
Intel^® 82801DB ICH4 Datasheet
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