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TMS320F28035: Diagnostic Oscillator Frequency Drift or Abnormal

Brian Wang0
Expert 5390 points
Part Number: TMS320F28035


Hi team,

My customer is trying to adding a oscillator frequency diagnostic as an safety enhancement.

In device like F28004x, we have DCC that can achieve this function. But in F2803x, seems we only have a missing clock logic which is capable of detecting clock loss but not frequency abnormal, is that correct? 

If customer would like to achieve this function on F28035, is there any recommended solution?

Regards,

Brian

  • 0
    TI__Guru* 81560 points

    Brian,

    While there is not a DCC or HW logic that will detect mis-matches between clocks on the F28035, I believe there does exist the proper connections for the customer to use SW to do similar type calculations as the DCC.

    There is an option to supply the CPUTIMER2 with a different clock than the SYSCLK(either external oscillator or one of the internal oscillators), as well as a pre-scaler.  In this manner, they could check the PLL vs its source clock in a similar fashion to the DCC.  There would be some CPU overhead, since the registers would need to be checked manually.

    This function is detailed in the TRM in this link in Table 1-23 bits 7-5 and 4-3 respectively   

    Please let me know if you have more questions.

    Best,

    Matthew