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TMS320F280049C: missing clock detection (MCD) switch over clock source

Part Number: TMS320F280049C


Tool/software:

Hi Champ,

I am asking for my customer.

They are having a 20 MHz external crystal as clock source.

They want to check if the external crystal suddenly fails, would the MCD module switch the clock source from external crystal to INTOSC1 fully automatically ?

From the TRM MCD sub-title, it shows the following occurs: 

  • The PLL is bypassed and OSCCLK is connected to INTOSC1 (after the PLLSYSCLK divider).

Is the meaning OSCCLK is connected to INTOSC1 telling that the hardware will automatically switch the clock source to INTOSC1 without a line to be manually configured by user, right ? or user indeed needs few lines for following actions if MCD detects there is a clock failure.

Thanks and regards,

Johnny

  • Hi Johnny, 

    Your understanding is correct. If MCD is enabled and a missing clock is detected, then the PLL is bypassed and all system clocks are connected to INTOSC1 automatically

    Additional details can be found in 3.7.12 Missing Clock Detection in the TRM.

    Best,

    Matt