PC87391 Datasheet, PDF (18/148 Pages) National Semiconductor (TI) – 100-Pin LPC SuperI/O Devices for Portable Applications

1.0 Signal/Pin Connection and Description (Continued)
1.5 DETAILED SIGNAL/PIN DESCRIPTIONS
This section describes all the signals used in the PC8739x family. Some members of the PC8739x family implement
a subset of these signals. Refer to the table on page 3 to identify the functions relevant to a specific device.
1.5.1 Bus Interface
Signal Pin(s) I/O Buffer Type Power Well
Description
LAD3-0 18-15
LCLK
8
LDRQ
11
LFRAME 12
LRESET 9
SERIRQ 10
I/O IN_PCI/O_PCI
I
IN_PCI
O
O_PCI
I
IN_PCI
I
IN_PCI
I/O IN_PCI/O_PCI
SMI
19
LPCPD 7
CLKRUN 6
OD
OD₁₂
I
IN_PCI
I/OD IN_PCI/OD₁₂
V_DD LPC Address-Data. Multiplexed command, address bi-
directional data and cycle status.
V_DD LPC Clock. Same 33 MHz clock as the PCI clock.
V_DD LPC DMA Request. Encoded DMA request for LPC interface.
V_DD LPC Frame. Low pulse indicates the beginning of new LPC
cycle or termination of a broken cycle.
V_DD LPC Reset. Practically the PCI system reset.
V_DD Serial IRQ. The interrupt requests are serialized over a single
pin, where each IRQ level is delivered during a designated time
slot.
V_DD System Management Interrupt
V_DD Power Down. Indicates that power is going to be shut on the
LPC interface.
V_DD Clock Run. Indicates that LCLK is going to be stopped, and
requests full-speed LCK (same as PCI CLKRUN).
1.5.2 Clock
Signal
CLKIN
Pin(s) I/O Buffer Type Power Well
Description
20
I
IN_T
V_DD Clock In. Active clock input signal of 32.768 KHz, 14.318 MHz or
48 MHz.
1.5.3 Infrared (IR)
Signal Pin/s I/O Buffer Type Power Well
Description
IRRX1
69
I
IN_TS
IRRX2_IRSL0 68
I/O IN_TS/O_3/6
IRSL1
67
I/O IN_T/O_3/6
IRSL2
71, 34 I/O IN_T/O_3/6
IRSL3
66
I
IN_T
IRTX
70
O
O_6/12
V_DD IR Receive 1. Primary input to receive serial data from the IR
transceiver. Monitored during power-off for wake-up event
detection.
V_DD IRRX2 - IR Receive 2. Auxiliary IR receiver input to support a
second transceiver. Monitored during power-off for wake-up event
V_{DD detection.}
V_DD
IRSL3-0 IR Select. Outputs are used to control the IR transceivers.
Input for PnP identification of plug-in IR transceiver (dongle).
V_DD After reset, the dual function IRSLX pins wake up in input mode.
After the ID is read by the IR driver, these pins can be put into
output mode. The output mode is controlled by Serial Port 2.
V_DD IR Transmit. IR serial output data.
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