2.4.2 PA00
Note that PA00 is multiplexed with TCK. PA00 GPIO function must only be used as output in theapplication.
2.4.3 RESET_N Pin
The RESET_N pin is a schmitt input and integrates a permanent pull-up resistor to VDDIN. Asthe product integrates a power-on reset detector, the RESET_N pin can be left unconnected incase no reset from the system needs to be applied to the product.The RESET_N pin is also used for the aWire debug protocol. When the pin is used for debugging,it must not be driven by external circuitry.
2.4.4 TWI Pins PA21/PB04/PB05
When these pins are used for TWI, the pins are open-drain outputs with slew-rate limitation andinputs with spike filtering. When used as GPIO pins or used for other peripherals, the pins havethe same characteristics as other GPIO pins. Selected pins are also SMBus compliant (refer toSection 3.2 on page 9). As required by the SMBus specification, these pins provide no leakagepath to ground when the AT32UC3L016/32/64 is powered down. This allows other devices on
the SMBus to continue communicating even though the AT32UC3L016/32/64 is not powered.After reset a TWI function is selected on these pins instead of the GPIO. Please refer to theGPIO Module Configuration chapter for details.
2.4.5 TWI Pins PA05/PA07/PA17
When these pins are used for TWI, the pins are open-drain outputs with slew-rate limitation andinputs with spike filtering. When used as GPIO pins or used for other peripherals, the pins have
the same characteristics as other GPIO pins.