AnsweredAssumed Answered

i.MX7D Regarding TEMPMON without RTC XTAL 

Question asked by Tomohisa Sakamoto on Jun 6, 2017
Latest reply on Jun 7, 2017 by igorpadykov

Dear Support-team.


Our customer do not use RTC(32KHz).
But customer want to use TEMPMON(Temperature Monitor).


Even if we do not use the 32 KHz RTC, it looks like i.MX7D can be used with 40 KHz RingOSC.
(i.MX7DRM.pdf) Rev. 0.1 Oscillator

Either the 32KHz XTAL or the 40KHz RingOSC can be used as the source of the 32KHz
clock to CCM and then get delivered to the rest of the SoC. Due to the 32KHz XTAL
start up time, 40KHz RingOSC is selected as the default clock source during SoC power
up. Once the 32KHz XTAL starts up, the clock source will be switched to it
automatically and the 40KHz RingOSC will be shut off. If the 32KHz XTAL stops in
some case, the 40KHz RingOSC will be enabled and selected as the source. The enable/
disable of the 40KHz RingOSC and the clock source switching is done automatically in
HW and there is no programmable register for SW to select the clock source. There is
only one read-only register to show the current clock source.


Can we use TEMPMON without 32 KHz RTC?
If yes,
1) Do we need any special setting?
2) Please also let me know if you have any caveats.


Best Regards,