PC87391 Datasheet, PDF (138/148 Pages) National Semiconductor (TI) – 100-Pin LPC SuperI/O Devices for Portable Applications

9.0 Device Characteristics (Continued)
6. 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 KΩ pull-up resistors should be used.
7. Output from STB, AFD, INIT, 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 KΩ pull-up resistors should be
used.
8. I_OH is valid for a GPIO pin only when it is not configured as open-drain.
9.3 INTERNAL RESISTORS
9.3.1 Pull-Up Resistor
Symbol: PU_nn.
Symbol
Parameter
R_PU Pull-up equivalent resistance
Conditions
V_PIN = V_DD = 3.3V
Min Typical Max Unit
nn-30% nn nn+30% KΩ
9.3.2 Pull-Down Resistor
Symbol: PD_nn.
Symbol
Parameter
R_PD Pull-down equivalent resistance
Conditions
Min Typical Max Unit
V_PIN = 0V, V_DD = 3.3V nn-30% nn nn+30% KΩ
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