informations about teensy 3.6 timers

[alfredDebug]

Hey, i'm would have some informations about the teensy 3.6 timers. Exactly, i'd like to control the counter of one timer. I searched for a long and i don't understand.

1 The counter of the timer can start counting from zero, if we order it, whithout loading some value. OR we should load some value first?
2 How can i access to the counter and load some value?
3 How can i enable start counting and the overflow bit?

Thank u for your help

 

[PaulStoffregen]

Teensy 3.6 has many different types of timers. Here's a quick summary.

https://www.pjrc.com/teensy/techspecs.html

They're all fully documented in the reference manual, available here:

https://www.pjrc.com/teensy/datasheets.html

The timers involve many complex details. Perhaps a good first step would be to see if IntervalTimer (which uses the PIT timers) can meet your needs?

https://www.pjrc.com/teensy/td_timing_IntervalTimer.html

If not, perhaps start reading the FTM timers info in chapter 45 starting on page 1127. I believe all the things you've asked can be found in just 2 or 3 registers. The main one is FTM0_SC documented on page 1144. The following pages document the actual count register. If you want to pre-load the count to something other than zero, also look at FTM0_CNTIN on page 1150.

The FTM timers have a ton of complex waveform features. It's a huge amount of reading material. But just starting, stopping, and setting the timer to a specific value are pretty simple.

However, if your purpose (which you didn't explain... so this message isn't nearly as helpful at it could have been) is merely to run a function as an interrupt every time the timer overflows, your needs will probably be met by the easy-to-use IntervalTimer object. Then again, if you need more or just enjoy digging into hardware details, it's all there waiting for you...