E
82371AB (PIIX4)
31
4/9/97 2:23 PM PIIX4aDS
INTEL CONFIDENTIAL
(until publication date)
PRELIMINARY
Name
Type
Description
SDA[2:0]
O
SECONDARY DISK ADDRESS[2:0].
These signals indicate which byte in either the
ATA command block or control block is being addressed. If the IDE signals are
configured for Primary and Secondary, these signals are connected to the
corresponding signals on the Secondary IDE connector.
If the IDE signals are configured for Primary Master and Primary Slave, these signals
are used for the Primary Slave connector.
During Reset:
High-Z
After Reset:
Undefined
1
During POS:
SDA
SDCS1#
O
SECONDARY CHIP SELECT FOR 170H
177H RANGE.
For ATA command register
block. If the IDE signals are configured for Primary and Secondary, this output signal is
connected to the corresponding signal on the Secondary IDE connector.
If the IDE signals are configured for Primary Master and Primary Slave, these signals
are used for the Primary Slave connector.
During Reset:
High
After Reset:
High
During POS:
High
SDCS3#
O
SECONDARY CHIP SELECT FOR 370H
377H RANGE.
For ATA control register
block. If the IDE signals are configured for Primary and Secondary, this output signal is
connected to the corresponding signal on the Secondary IDE connector.
If the IDE signals are configured for Primary Master and Primary Slave, these signals
are used for the Primary Slave connector.
During Reset:
High
After Reset:
High
During POS:
High-Z
SDD[15:0]
I/O
SECONDARY DISK DATA[15:0].
These signals are used to transfer data to or from the
IDE device. If the IDE signals are configured for Primary and Secondary, these signals
are connected to the corresponding signals on the Secondary IDE connector.
If the IDE signals are configured for Primary Master and Primary Slave, these signals
are used for the Primary Slave connector.
During Reset:
High-Z
After Reset:
Undefined
1
During POS:
SDD
SDDACK#
O
SECONDARY DMA ACKNOWLEDGE.
This signal directly drives the IDE device
DMACK# signal. It is asserted by PIIX4 to indicate to IDE DMA slave devices that a
given data transfer cycle (assertion of SDIOR# or SDIOW#) is a DMA data transfer
cycle. This signal is used in conjunction with the PCI bus master IDE function. It is not
associated with any AT compatible DMA channel.
If the IDE signals are configured for Primary and Secondary, this signal is connected to
the corresponding signal on the Secondary IDE connector.
If the IDE signals are configured for Primary Master and Primary Slave, these signals
are used for the Primary Slave connector.
During Reset:
High
After Reset:
High
During POS:
High