Arduino Zero timer setup
BOTTOM UP

The arduino Zero uses an Atmel samd21 µController. This video explains how to program the samd chips in a bottom up fashion, or at least how to gather all required information to do so. In case the video doesn't work anymore, i'll briefly rephrase it here. The main steps are:


Figure out the required registers by reading the data sheet
Consult the Atmel Software Framework(ASF) to figure out the corresponding data structures
Setup your sketch inside the arduino IDE


The bottom up process can be very time consuming, because you are searching a needle out of an haystack like, the datasheet and the ASF. So you need to tackle all the tiny bits before building the whole thing.

TOP DOWN

For some situations it is better to look for a working example program and try to figure out how its done. For this i recommend the arduino github repository. It is a very good resource for figuring out how arduino uses the ASF and helps me tune certain functions.

The top down process therefore allows to decompose a large working function into its smaller parts and dig into the interesting parts. However, it requires something to work with at the start which is not always available.

INDECIPHERABLE

Some code examples aren't understandable from the start. Once you know what the code is doing, i recommend splitting up the large pieces like this register and bit modification section into smaller ones. Extract these sections into functions with self explanatory names, and if done correctly you can get rid of the comments.

Hope this helps ;)