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TMS570 CRC capabilities data

Jon Bilbao
Intellectual 1425 points

Hi All,

We would like to ask for the TMS570 CRC capabilities data.

We need to prove that the internal hardware CRC of the TMS CPU (64bit) meets our requirements.

The most essential question that needs to be answered for us at this moment is how probably is that the CRC of the TMS CPU is correct even though the data is corrupted?

also, Can you please provide us the analysis of CRC of the TMS?

regards,

Jon

  • 0
    TI__Guru 59540 points
    Hello Bilbao,

    The module uses a maximum length polynomial. It is supposed to be unique up to 2^64. However, there is no formal study on total effectiveness of the calculated CRC that I am aware of.

    For your reference, the CRC algorithm used is included in the TRMs for the Hercules devices in case you want to gain more information about it or if your customer wants to exercise the algorithm to analyze the effectiveness on their own. Given the broad spectrum of combinations of bits, (2^64)!, and the inclusion of seed values, I would expect the analysis to be very long and arduous.

    Is there a specific metric that your customer is looking to achieve?
  • 0 in reply to Chuck Davenport
    Prodigy 10 points
    Hello,

    Thank you for posting our question and for the reply.
    However, we are a bit confused and we need to ask for additional clarifications.
    According to the “Safety Manual for TMS570LS31x and TMS570LS21x Hercules™ ARM®-Based Safety Critical Microcontrollers” User Manuel, ISO-CRC-64 is used (e.g. part 7.35 of mentioned document) . This polynomial is considered as a shortened one, and has a polynomial representation: x^64+x^4+x^3+x+1. Thus, it is not full a length polynomial, like CRC-64-ECMA-182 for example and that is why the “robustness” of 2^64 is questionable.

    Best regards,
    Jelena Kaitovic

    Dr. techn. Jelena Kaitovic - Project Engineer Aerospace
    TTTech Computertechnik AG
    Schoenbrunner Strasse 7, A-1040 Vienna, Austria
    Tel: +43 1 585 34 34-4237
    jelena.kaitovic@tttech.com, www.tttech.com
  • 0 in reply to Jelena Kaitovic
    TI__Guru 59540 points
    Hello Dr.Kaitovic,

    The CRC algorithm used within the CRC module of the device is documented fairly extensively within the Technical Reference Manual of the device. I am unaware of any technical assessments of the effectiveness of the module but it has been used for many years within the automotive and other industries without any issues of which I am aware.

    As far as it's suitability for the Aerospace industry, you are welcome to draw your own conclusions based on available data for the ISO-CRC-64 standard and review of the information within the TRM. If it isn't suitable for your application, it is always possible to revert to coding your specific CRC implementation in software.

    Regards,
    Chuck Davenport