SAMR21 Implementation

I've got some questions about the implementation of RIOT on the SAMR21:

   - RNG: There is no HW module in samd21 but the transceiver at86rf233    provides one (see 40.2 in datasheet). Should we implement it anyway?    - Concerning the MCU, I've seen that "Energy saving modes not fully    utilized", what is it missing exactly?    - What's the difference between RTT (Real Time Timer) and RTC (Real Time    Counter) for the SAMR21?

Regards,

Hi,

I've got some questions about the implementation of RIOT on the SAMR21:

   - RNG: There is no HW module in samd21 but the transceiver at86rf233    provides one (see 40.2 in datasheet). Should we implement it anyway?

Yes, the source for random data is up to the platform. As long as it's documented it can even be an unconnected pin of the CPU.

   - What's the difference between RTT (Real Time Timer) and RTC (Real Time    Counter) for the SAMR21?

From the RIOT documentation of the RTC interface:

"Low-level RTC (Real Time Clock) peripheral driver." The RTC is intended to count calendar time, not system time. Therefore it is treated differently from other timers. Refer to the R21 datasheet chapter 17. for details.

Cheers, Ludwig

Thanks for the answer.

I’m going to implement RNG for the SAMR21 then. Ok for the RTC.

How about the Energy Saving (MCU) for the SAMR21?

Cheers,

Baptiste

Hey Baptiste,

would you mind to make a note in the issue-tracker [1] ?

Cheers, Peter

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