8224 N/B Maintenance
8224 N/B Maintenance
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5.2 Intel ICH7-M South Bridge (4)
IDE Interface Signals
Name Type
Description
DCS1#
O
IDE Device Chip Selects for 100 Range:
For ATA command register block. This output signal is connected to
the corresponding signal on the IDE connector.
DCS3#
O
IDE Device Chip Select for 300 Range:
For ATA control register block. This output signal is connected to the
corresponding signal on the IDE connector.
DA[2:0]
O
IDE Device Address:
These output signals are connected to the corresponding signals on
the IDE connector. They are used to indicate which byte in either the
ATA command block or control block is being addressed.
DD[15:0]
I/O
IDE Device Data:
These signals directly drive the corresponding signals on the IDE
connector. There is a weak internal pull-down resistor on DD7.
DDREQ
I
IDE Device DMA Request:
This input signal is directly driven from the DRQ signal on the 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. There is a
weak internal pulldown resistor on this signal.
DDACK#
O
IDE Device DMA Acknowledge:
This signal directly drives the DAK# signal on the IDE connector.
DDACK# is asserted by the Intel
®
ICH7 to indicate to IDE DMA
slave devices that a given data transfer cycle (assertion of DIOR# or
DIOW#) is a DMA data transfer cycle. This signal is used in
conjunction with the PCI bus master IDE function and are not
associated with any AT-compatible DMA channel.
DIOR#/
(DWSTB/
RDMARDY#)
O
DIOR# /Disk I/O Read (PIO and Non-Ultra DMA):
This is the command to the IDE device that it may drive data onto the
DD lines. Data is latched by the ICH7 on the deassertion edge of
DIOR#. The IDE device is selected either by the ATA register file
chip selects (DCS1# or DCS3#) and the DA lines, or the IDE DMA
acknowledge (DDAK#).
Disk Write Strobe (Ultra DMA Writes to Disk): This is the data write
strobe for writes to disk. When writing to disk, ICH7 drives valid data
on rising and falling edges of DWSTB.
Disk DMA Ready (Ultra DMA Reads from Disk): This is the DMA
ready for reads from disk. When reading from disk, ICH7 deasserts
RDMARDY# to pause burst data transfers.
IDE Interface Signals (Continued)
Name Type
Description
DIOW#/
(DSTOP)
O
Disk I/O Write (PIO and Non-Ultra DMA):
This is the command to the IDE device that it may latch data from the
DD lines. Data is latched by the IDE device on the deassertion edge
of DIOW#. The IDE device is selected either by the ATA register file
chip selects (DCS1# or DCS3#) and the DA lines, or the IDE DMA
acknowledge (DDAK#).
Disk Stop (Ultra DMA): ICH7 asserts this signal to terminate a burst.
IORDY/
(DRSTB/
WDMARDY#)
I
I/O Channel Ready (PIO):
This signal will keep the strobe active (DIOR# on reads, DIOW# on
writes) longer than the minimum width. It adds wait-states to PIO
transfers.
Disk Read Strobe (Ultra DMA Reads from Disk): When reading from
disk, ICH7 latches data on rising and falling edges of this signal from
the disk.
Disk DMA Ready (Ultra DMA Writes to Disk): When writing to
disk, this is deasserted by the disk to pause burst data transfers.
System Management Interface Signals
Name Type
Description
INTRUDER#
I
Intruder Detect:
This signal can be set to disable system if box detected open.
This signal’s status is readable, so it can be used like a GPIO if the
Intruder Detection is not needed.
SMLINK[1:0]
I/OD
System Management Link:
SMBus link to optional external system management ASIC or LAN
controller. External pull-ups are required. Note that SMLINK0
corresponds to an SMBus Clock signal, and SMLINK1 corresponds
to an SMBus Data signal.
LINKALERT#
I/OD
SMLink Alert:
Output of the integrated LAN and input to either the integrated ASF
or an external management controller in order for the LAN’s
SMLINK slave to be serviced.
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