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MSPM0G3507: MSPM0G3507 RTC accuracy

Makoto Oka
Prodigy 320 points
Part Number: MSPM0G3507

Can you please take a look and comment on this?

The accuracy of the RTC is stated as +/- 240 ppm, what should they do to change it to +/- 30 ppm? Also, if they want to compensate by temperature, what should they do?

Is there the ability to run the program while the Data Flash is being updated (erased + written)? (Can the program run with the update process deferred to the task?) Or will it be the time wait below during the update?

  • 0
    Guru 42085 points

    For the first, use an external crystal.

  • 0 in reply to Keith Barkley
    TI__Mastermind 28075 points

    Hi Makoto,

    As Keith said, an external crystal will greatly help the accuracy of the RTC when compared to the internal LFCLK. 

    I don't see that the accuracy of the RTC is +/-240ppm, it should mostly be governed by the accuracy of the clock source. I do see that the calibration of the RTC allows for up to +/- 240PPM of adjustment. Across temperature you can update that value based on the expected drift of your clock source, to try and improve accuracy over temp.

    There may be low frequency crystals accurate enough that you don't really need to do this for your temperature range, but the calibration functionality is provided incase you do want to adjust it.

    Makoto Oka said:
    Is there the ability to run the program while the Data Flash is being updated (erased + written)? (Can the program run with the update process deferred to the task?) Or will it be the time wait below during the update?

    Not in this device no, you would need to have a device with dual-bank memory (those are not yet available, but are planned). You could run from SRAM while updating the flash memory, but that would be complicated to implement, as you must ensure you do not accidentally jump back to executing from the flash memory you are writing to.

    Best Regards,
    Brandon Fisher