The maximum clock frequency is 12 MHz, but it can be overclocked up to 18 MHz with some limitations.
The oscillator settings can be configured using the OSCCFG register. The register settings depend on the crystal frequency and the desired clock frequency.
The watchdog timer is used to reset the microcontroller in case of a software fault or a system crash. It can be enabled or disabled using the WDTE bit in the WDTMOD register.
The UART interface can be used for serial communication. The UART settings can be configured using the UCFG register, and the transmit and receive data can be accessed using the UART data registers.
The maximum current that can be sourced or sunk by the GPIO pins is 20 mA per pin, with a total current limit of 100 mA for all pins combined.