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TRF7970A: TRF7970A - Different Silicon Versions with different SPI-Modes by write/read

Valentin Robl
Prodigy 10 points
Part Number: TRF7970A

Hello everyone,

in an investigation it was examined whether the TRF7970 is correctly controlled via SPI, it at his point it seems to be good.

By Checking the Datasheet (Version: SLOS743B - August 2011 - Revised March 2012)  describes the SPI Mode for writing with SPI in Mode 0 and Read SPI in Mode 1. The Datasheet in Version: SLOS743M – AUGUST 2011 –REVISED MARCH 2020 describes SPI MODE 1 for writing and reading. (see attached image). The linux kernel driver implements for writing and reading mode 1, this behavior was confirmed on the SPI Bus.

/resized-image/__size/320x240/__key/communityserver-discussions-components-files/667/Compared-Datasheets.png  

My Questions:

  • Are there several silicon versions with different behavior of the chip's SPI modes on market?
  • or is the "old" Datasheet completely wrong (see link above of the compared datasheets).

Thanks a lot for your help

  • 0
    TI__Prodigy 295 points

    Hello,

    Thank you for your question and interest in our products.

     

    Please reference the most recent datasheet for this product(s).

     

    While TI strives to have the most accurate information in a datasheet at initial product launch, from time to time TI will offer an errata or an update to the datasheet.

     

    Thanks

    Chris

  • 0 in reply to Christopher Towle
    Prodigy 10 points

    Hello Chris, thanks for your answer.

    My problem is that the datasheets have controversy information for configuration of the SPI MODI in the datasheet versions 2012 and the last one from 2020.

    The datasheet from 2020 has only given the Revision History from March 28 2017 to March 11, 2020, so i can not find any information about SPI Changes.
    The older datasheet have was founded with the help of google.

    The Silicon Errata (Rev. B from 2016 only document available) does not mention any changes on the SPI-BUS, or erros respecting the problem with the modi without Chip Select. I am currently investigating witch SPI-MODI is required. (We have here chips which are about 8 years old..)

    Can you give me a hint, were i can get a specific Datasheet version this chip, for further investigation an clearance?

    Thanks

    Valentin

  • +1 in reply to Valentin Robl
    TI__Prodigy 295 points

    Valentin, Yes please use most recent data sheet for updated information.   

    SLOS743B D/S description is incorrect. See below for screen snippet from datasheet B and M side by side. The left side is the B version. For the B version where it is underlined with red, it is correct that the MOSI transition on the rising edge and sampled by the reader on the falling. In the detailed description where it is highlighted in yellow, the description shows the opposite which is wrong. For the M version on the right, it is correct.

  • 0 in reply to Christopher Towle
    Prodigy 10 points

    Hi Chris,

    thanks a lot.

    Thanks

    Valentin