
11.0 Device Characteristics
(Continued)
Revision 1.2
235
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P
11.2.7
Symbol:
OD
n
Output, TTL Compatible Open-Drain output buffer capable of sinking
n
mA. Output from these signals is open-drain and
is never forced high.
Output, Open-Drain Buffer
11.2.8
Symbol:
O
PCI
Output, PCI 3.3V
11.2.9
1. All pins are 5V tolerant except for the pins with PCI (IN
PCI
, O
PCI
) buffer types.
2. All pins are back-drive protected except for the pins with PCI (IN
PCI
, O
PCI
) and oscillator (O
OSC
) buffer types.
3. The following pins have an internal static pull-up resistor (when enabled) and therefore may have leakage current to
V
SUP
(when V
IN
= 0): ACK, AFD_DSTRB, ERR, INIT, PE, SLIN_ASTRB, STB_WRITE, PPDIS, P12, P16, P17, ACBCLK,
ACBDAT, PWBTIN, SLBTIN, PWBTOUT, GPIO00-07, GPIOE10-17, GPIO20-27, GPIO30-37, GPIOE40-47, GPIO50-55
and GPIO60-64.
4. The following pins have an internal static pull-down resistor (when enabled) and therefore may have leakage current to
V
SS
(when V
IN
= V
SUP
): BUSY_WAIT, PE and SLCT.
5. The following strap pins have an internal static pull-down resistor enabled during power-up reset and therefore may have
leakage current to V
SS
(when V
IN
= V
SUP
): BADDR, TRIS, CKIN48, XCNF2-0 and ACBSA.
6. When V
DD
= 0V, the following pins present a DC load to V
SS
of 30 K
minimum (not tested, guaranteed by design) for
a pin voltage of 0V to 3.6V: CTS1, CTS2, DCD1, DCD2, DSR1, DSR2, DTR1_BOUT1, DTR2_BOUT2, RI1, RI2, RTS1,
RTS2, SIN1, SIN2, SOUT1, SOUT2.
7. Output from SLCT, BUSY_WAIT (and PE if bit 2 of PP Confg0 register is 0) is open-drain in all SPP modes except in
SPP-Compatible mode when the setup mode is ECP-based FIFO and bit 4 of the Control2 parallel port register is 1.
Otherwise, output from these signals is level 2. External 4.7 K
pull-up resistors should be used.
8. Output from ACK, ERR (and PE if bit 2 of PP Confg0 register is set to 1) is open-drain in all SPP modes except in SPP-
Compatible mode when the setup mode is ECP-based FIFO and bit 4 of the Control2 parallel port register is set to 1.
Otherwise, output from these signals is level 2. External 4.7 K
pull-up resistors should be used.
9. Output from STB, AFD, INIT and SLIN is open-drain in all SPP modes, except in SPP-Compatible mode when the setup
mode is ECP-based (FIFO). Otherwise, output from these signals is level 2. External 4.7 K
pull-up resistors should be
used.
10. I
OH
is valid for a GPIO pin only when it is not configured as open-drain.
Exceptions
11.2.10 Terminology
Back-Drive Protection.
A pin that is back-drive protected does not sink current into the supply when an input voltage higher
than the supply, but below the pin’s maximum input voltage, is applied to the pin. This is true even when the supply is inac-
tive. Note that active pull-up resistors and active output buffers are typically not back-drive protected.
5-Volt Tolerance.
An input signal that is 5V tolerant can operate with input voltage of up to 5V even though the supply to
the device is only 3.3V. The actual maximum input voltage allowed to be supplied to the pin is indicated by the maximum
high voltage allowed for the input buffer. Note that some pins have multiple buffers, not all of which are 5V tolerant. In such
cases, there is a note that indicates at what conditions a 5V input may be applied to the pin; if there is no note, the low max-
imum voltage among the buffers is the maximum voltage allowed for the pin.
Symbol
Parameter
Conditions
Min
Max
Unit
V
OL
Output Low Voltage
I
OL
=
n
mA
0.4
V
I
OL
= 50
μ
A
0.2
V
Symbol
Parameter
Conditions
Min
Max
Unit
V
OH
Output High Voltage
l
out
=
500
μ
A
0.9 V
DD
V
V
OL
Output Low Voltage
l
out
=1500
μ
A
0.1 V
DD
V