Signal Definitions (Continued)
2.1 PIN ASSIGNMENTS
The tables in this section use several common abbrevia-
tions. Table 2-1 lists the mnemonics and their meanings.
Table 2-1. Pin Type Definitions
Mnemonic Definition
Standard input pin.
Figure 2-2 shows the pin assignment for the 352 BGA with
Table 2-2 and Table 2-3 listing the pin assignments sorted
by pin number and alphabetically by signal name, respec-
tively.
I
I/O
O
Bidirectional pin.
Totem-pole output.
OD
Open-drain output structure that
allows multiple devices to share the
pin in a wired-OR configuration.
Figure 2-3 shows the pin assignment for the 320 SPGA
with Table 2-4 and Table 2-5 listing the pin assignments
sorted by pin number and alphabetically by signal name,
respectively.
PU
Pull-up resistor.
PD
Pull-down resistor.
In Section 2.2 “Signal Descriptions” on page 31 a descrip-
tion of each signal is provided within its associated func-
tional group.
s/t/s
Sustained tri-state an active-low tri-
state signal owned and driven by
one and only one agent at a time.
The agent that drives an s/t/s pin low
must drive it high for at least one
clock before letting it float. A new
agent cannot start driving an s/t/s
signal any sooner than one clock
after the previous owner lets it float.
A pull-up resistor on the mother-
board is required to sustain the inac-
tive state until another agent drives
it.
VCC (PWR)
VSS (GND)
#
Power pin.
Ground pin.
The "#" symbol at the end of a signal
name indicates that the active, or
asserted state occurs when the sig-
nal is at a low voltage level. When
"#" is not present after the signal
name, the signal is asserted when at
a high voltage level.
t/s
Tri-state signal.
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