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Signal Description
2-4
82801AA and 82801AB Datasheet
2.4
IDE Interface
SERR#
I
System Error:
SERR# can be pulsed active by any PCI device that detects a system
error condition. Upon sampling SERR# active, the ICH has the ability to generate an
NMI, SMI#, or interrupt.
PME#
I
PCI Power Management Event:
PCI peripherals drive PME# to wake the system from
low-power states S1-S5.
REQ[A]# /
GPIO [0]
REQ[B]#/
REQ[5]# /
GPIO[1]
I
PC/PCI DMA Request [A:B]:
This request serializes ISA-like DMA Requests for the
purpose of running ISA-compatible DMA cycles over the PCI bus. This is used by
devices such as PCI based Super I/O or audio codecs which need to perform legacy
8237 DMA but have no ISA bus.
When not used for PC/PCI requests, these signals can be used as General Purpose
Inputs.
NOTES:
1. For the 82810AA, REQ[B]# can instead be used as the 6th PCI bus request.
2. REQ[5]# (shown in column 1) is only available on the ICH (82801AA).
GNT[A]#/
GPIO[16]
GNT[B]#
/
GNT[5]# /
GPIO[17]
O
PC/PCI DMA Acknowledges [A: B]:
This grant serializes an ISA-like DACK# for the
purpose of running DMA/ISA Master cycles over the PCI bus. This is used by devices
such as PCI based Super/IO or audio codecs that need to perform legacy 8237 DMA
but have no ISA bus. External pull-up resistors are not required. If external pull-up
resistors are used, they must be tied to the VCC3_3 power rail.
When not used for PC/PCI, these signals can be used as General Purpose Outputs.
NOTES:
1. For the 82810AA, GNTB# can also be used as the 6th PCI bus master grant
output.
2. GNT[5]# (shown in column 1) is only available on the ICH (82801AA).
Table 2-4. IDE Interface Signals (Sheet 1 of 2)
Name
Type
Description
PDCS1#,
SDCS1#
O
Primary and Secondary IDE Device Chip Selects for 100 Range:
For ATA
command register block. This output signal is connected to the corresponding
signal on the primary or secondary IDE connector.
PDCS3#,
SDCS3#
O
Primary and Secondary IDE Device Chip Select for 300 Range:
For ATA control
register block. This output signal is connected to the corresponding signal on the
primary or secondary IDE connector.
PDA[2:0],
SDA[2:0]
O
Primary and Secondary IDE Device Address:
These output signals are
connected to the corresponding signals on the primary or secondary IDE
connectors. They are used to indicate which byte in either the ATA command block
or control block is being addressed.
PDD[15:0],
SDD[15:0]
I/O
Primary and Secondary IDE Device Data:
These signals directly drive the
corresponding signals on the primary or secondary IDE connector.
PDDREQ,
SDDREQ
I
Primary and Secondary IDE Device DMA Request:
These input signals are
directly driven from the DRQ signals on the primary or secondary IDE connector. It
is asserted by the IDE device to request a data transfer, and used in conjunction
with the PCI bus master IDE function and are not associated with any AT
compatible DMA channel.
Table 2-3. PCI Interface Signals (Sheet 3 of 3)
Name
Type
Description