Hi Daniel and parnal,
I've added the counter using the TC3 and TC4 timers in 32-bit mode. In this mode, TC4 acts as the master and TC3 the slave, this just means that the registers are accessed through TC4's interface.
The TC4 timer in 32-bit mode is set-up to increment each time it receives an event from interrupt pin on the event system.
Using 32-bits with a 40kHz input frequency will allow the TC timer to count for almost 30 hours before rolling over back to 0.
If you require longer than this then it'll be necessary to get TC4 to generate an overflow event to the 16-bit TC5 timer. Using TC5 as well will give you 223 years before it rolls over! Probably enough for most projects, in any case we won't be around when this happens.
Please find the code attached. Unfortunately it exceeds the 9000 character limit, so I can't display it in this message.
Kind regards,
Martin
TCCCapture_DMAC_TCCount.ino (8.95 KB)