Interrupt service routine timer library for an Atmel SAMD51 microprocessor board, like Adafruit M4 Metro/Feather/ItsyBitsy Express. The library only offers the use of clock TC3. Can be imported into the Arduino IDE as a zip file.
Method names mimic the 'ZeroTimer' library by Tamasa (@EHbtj) for easily switching compilation between SAMD21 and SAMD51 microprocessor boards. See https://github.com/EHbtj/ZeroTimer for the SAMD21 library.