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*****

santosh Krishnan
Prodigy 10 points

Part Number: *****>

  • +1
    TI__Mastermind 19657 points
    santosh Krishnan said:
    setting the startup time to 19

    If you need min MSPM0 boot time, you need to test for a min start up time of HFXT, to speed up the total startup time.

    At the same time, this startup time need to be enough for HFXT to startup, in other word, make sure HFXT can 100% start successfully.

    santosh Krishnan said:
    Shouldn’t it also be possible to set the startup time to the minimum value (e.g., 1), and check the HFCLK CLKSTATUS status in a loop with a timeout?

    It doesn't work the way you think.

    You need to make sure the startup time is long enough for HFXT, not waiting for HFXT ready in loop.

    Please follow the recommendation above to set a reasonable value.

  • 0 in reply to Helic Chi
    Prodigy 10 points

    Thank you for your reply and explanation.

    I just want to confirm my understanding: Let’s say the HFXT crystal starts up fully in just 2 ms. However, if I’ve configured the startup time to the maximum value (0xFF), which corresponds to 16.3 ms (i.e., 64 µs × 255),

    Then: Arrow right️ I still need to wait the full 16.3 ms in a loop, for checking the CLKSTATUS register for an update.

    As stated in the datasheet: “In the case of HFXT being used, after the specified HFXT startup time has expired,

    the HFXT status is tested. If the HFXT started successfully, the HFXT startup monitor asserts the HFCLKGOOD bit in

    the CLKSTATUS register.”

    So, there’s a trade-off here:

     White check mark Faster startup with particular crystal: By configuring the startup time to the minimum required for a specific crystal.

     Shield️ More compatibility but with lengthy starting process:  By using the maximum startup time, which works reliably with most crystals but introduces unnecessary delay even if the crystal starts faster.

    Thanks in advance!

  • 0 in reply to santosh Krishnan
    TI__Mastermind 19657 points
    santosh Krishnan said:

    So, there’s a trade-off here:

      Faster startup with particular crystal: By configuring the startup time to the minimum required for a specific crystal.

     ️ More compatibility but with lengthy starting process:  By using the maximum startup time, which works reliably with most crystals but introduces unnecessary delay even if the crystal starts faster.

    Correct !