82371AB Datasheet, PDF (33/284 Pages) Intel Corporation – PCI-TO-ISA / IDE XCELERATOR PIIX4

E
82371AB (PIIX4)
Name Type
Description
SIORDY
I SECONDARY IO CHANNEL READY. In normal IDE mode, this input signal is directly
driven by the corresponding IDE device IORDY signal.
In an Ultra DMA/33 read cycle, this signal is used as STROBE, with the PIIX4 latching
data on rising and falling edges of STROBE. In an Ultra DMA write cycle, this signal is
used as the DMARDY# signal which is negated by the drive to pause Ultra DMA/33
transfers.
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.
This is a Schmitt triggered input.
NOTES:
1. After reset, all undefined signals on the primary channel will default to the same values as the undefined
signals on the secondary channel.
2.1.9. UNIVERSAL SERIAL BUS SIGNALS
Name
OC[1:0]#
USBP0+,
USBP0–
USBP1+,
USBP1–
Type
Description
I OVER CURRENT DETECT. These signals are used to monitor the status of the USB
power supply lines. The corresponding USB port is disabled when its over current signal
is asserted.
I/O SERIAL BUS PORT 0. This signal pair comprises the differential data signal for USB
port 0.
During Reset: High-Z
After Reset: High-Z
During POS: High-Z
I/O SERIAL BUS PORT 1. This signal pair comprises the differential data signal for USB
port 1.
During Reset: High-Z
After Reset: High-Z
During POS: High-Z
2.1.10. POWER MANAGEMENT SIGNALS
Name
BATLOW#/
GPI9
CPU_STP#/
GPO17
Type
Description
I BATTERY LOW. Indicates that battery power is low. PIIX4 can be programmed to
prevent a resume operation when the BATLOW# signal is asserted.
If the Battery Low function is not needed, this pin can be used as a general-purpose
input.
O CPU CLOCK STOP. Active low control signal to the clock generator used to disable
the CPU clock outputs. If this function is not needed, then this signal can be used as
a general-purpose output.
For values During Reset, After Reset, and During POS, see the Suspend/Resume
and Resume Control Signaling section.
PRELIMINARY
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4/9/97 2:23 PM PIIX4aDS
INTEL CONFIDENTIAL
(until publication date)