VDD
VDD
VDD
2 clocks
delay
Weak
Strong
Very weak
Port pin
Port latch data
Input data
Open-drain Output
The open-drain output configuration turns off all pull-ups and only drives the pull-down
transistor of the port pin when the port register contains a logic “0”. To use this configuration in
application, a port pin must have an external pull-up, typically tied to VDD. The input path of
the port pin in this configuration is the same as quasi-bidirectional mode.
Port pin
Port latch data
Input data
Input-only Mode
The input-only configuration is a Schmitt-triggered input without any pull-up resistors on the
pin.
Port pin
Input data
22
MPC82x54A Data Sheet
MEGAWIN