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Part Number: TMS320F28377D
Other Parts Discussed in Thread: TMS570LS3137


Can I ask your advice to implement a diagnostic for ADC MUX(multiplexer) ?

We would be glad if you could comment for hardware and software.

- Hardware: In case of Hercules (TMS570LS3137), 16 terminals are connected to both ADC1/2 and the duplicated readings can be compared. I think such duplicated ADC paths are not there in the F28377D. How TI has implemented a diagnostic on the F28377D to pass the IEC61508 SIL-3?

- Software: Is there a sample code to self-test the MUX? It would be like, many calls to the STL_ADC_test() in various MUX conifguration.

My point is not the ADC but the MUX.
I have downloaded the C2000-DIAGNOSTIC-SW-PACKAGE and found the STL_ADC_test() is a good solution for the ADC body or a single channel.

  • On the F28377D device, there are 3 ADC input pins that are routed to all 4 ADCs as the Hercules does, which are ADCINA0 routed to IN12 of each ADC, and ADCIN14/15 routed to IN14/15 of each ADC.

    In addition, on the F28377D, there are 4 ADCs, each have their own set of input pins. If the your system configurations allow it, you could use 2 ADCs to independently sample the input signals, through separate pins, and do a SW based cross-check (on the validity of the input) after the ADC results register has been written into.

    The F28377D device also have DAC loopback and VREFLO routed to IN8/9 of each ADC, which could also be used by customer as check for ADC/MUX.

    Please refer to the block diagram on page 96 of the datasheet (SPRS880H).
  • Hi Hideaki,

    Our safety experts will be responding shortly.

  • Han and Sal,
    Thank you. Very clear and very quick.