
1.0 Signal/Pin Connection and Description
(Continued)
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Revision1.2
P
1.2
The signal DC characteristics of the pins described in Section 1.4 are denoted by buffer type symbols, which are defined in
Table 1 and described in further detail in Section 11.2. The pin multiplexing information refers to two different types of mul-
tiplexing:
BUFFER TYPES AND SIGNAL/PIN DIRECTORY
G
Multiplexed, denoted by a slash (/) between pins in the diagrams in Section 1.1. Pins are shared between two differ-
ent functions. Each function is associated with different board connectivity. Normally, the function selection is deter-
mined by the board design and cannot be changed dynamically. The multiplexing options must be configured by the
BIOS upon power-up in order to comply with the board implementation.
G
Multiple Mode, denoted by an underscore (_) between pins in the diagrams in Section 1.1. Pins have two or more
modes of operation within the same function. These modes are associated with the same external (board)
connectivity. Mode selection may be controlled by the device driver through the registers of the functional block and
do not require a special BIOS setup upon power-up. These pins are not considered multiplexed pins from the
ServerI/O configuration perspective. The mode selection method (registers and bits), as well as the signal specifica-
tion in each mode, are described within the functional description of the relevant functional block.
Table 1. Buffer Types
1.3
The table below shows only multiplexed pins, their associated functional blocks and the configuration bits for the selection
of the multiplexed options used in the PC8741x.
Some PC8741x devices implement a subset of these signals.
Refer to
Device-Specific Information
on page 4 to identify the functions relevant to a specific device.
PIN MULTIPLEXING
Symbol
Description
IN
CS
Input, CMOS compatible, with Schmitt Trigger
IN
OSC
Input, from crystal oscillator (not characterized)
IN
PCI
Input, PCI 3.3V
IN
SM
Input, ACCESS.bus and SMBus compatible
IN
T
Input, TTL compatible
IN
TS
Input, TTL compatible, with Schmitt Trigger
IN
ULR
Input, power, resistor protected (not characterized)
O
p/n
Output, push-pull output buffer capable of sourcing
p
mA and sinking
n
mA
OD
n
Output, open-drain output buffer capable of sinking
n
mA
O
OSC
Output, to crystal oscillator (not characterized)
O
PCI
Output, PCI 3.3V
PWR
Power pin
GND
Ground pin