What is the resolution of micros() on SAMD 21 boards?

In the reference page here…
https://www.arduino.cc/en/Reference/Micros
it says that the resolution of the "micros()" function on 16 MHz AVR boards is 4 µs that is all returns are multiples of 4. And then on 8 MHz boards the resolution is 8 µs.

What is the resolution on SAMD 21 systems such as Arduino Zero?

Hi cyborg5,

The SAMD21's micros() function is based on the microcontroller's system ticker that has a resolution of 1µs.