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CARD-PCI/GX Hardware Manual
EPSON
Rev.A
22
Descriptions on symbols indicating these factors are shown below:
Symbol description
Item
Symbol
Description
I/O
Input/output
s/t/s
Sustained tri-state (reference PCI v2.1))
I/OD
Input and open drain output
I
Input only
O
Output only
OD
Open drain output
I/O
programmable
Input/output is set by software.
3.3V
Output is 0 to 3.3V. Input must be 0 to 3.3V.
3.3V ,5VT
Output is 0 to 3.3V. Input can be 0 to 5V. (5V input is TTL level.)
5VSTB
V
CCSTB
is supplied to the input/output element power supply.
Voltage
5V
Both input and output is 0 to 5.0V (5V input is TTL level.)
XpU(5V)
Pulled-up to 5V by resistance of x
Ω
inside SCE8720C.
xPU(3.3V)
Pulled-up to 3.3V by resistance of x
Ω
inside SCE8720C.
xPU(5VSTB)
Pulled-up to V
CCSTB
by resistance of x
Ω
inside SCE8720C.
xPD
Pulled-down by resistance of x
Ω
inside SCE8720C.
weak-PU
Pulled-up to 5V by Approx. 40k
Ω
resistance.
pull-up
/down
Weak-PD
Pulled-down by Approx. 40k
Ω
resistance.
I
OL
/I
OH
x/-y
Output drivability: sink current x, source current y
xPU(5V)
Pulled-up to 5V by x
Ω
resistance.
XPU(5VSTB) Pulled-up to V
CCSTB
by x
Ω
resistance.
Refe-
rence
PU/PD
XPU(3.3V)
Pulled-up to 3.3V by x
Ω
resistance.
pull-up
/down when
not used
PU
Even when not using the signal in the system, some kind of pull-
up is necessary. NC is not available.