• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 120 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LP8733: Auto-increment Feature at read

Kalman Budai
Intellectual 580 points

Part Number: LP8733

Dear TI,

chapter 7.5.1.5 of SNVSBK2A document states that: "The auto-increment feature
does not work for read"

I have written a small program, which can read all registers one-by-one and in a single burst. There is no deviation between the results.

PMIC>d (single read)
0000: 82 4D 07 2C  07 2B 2F FC  07 07 0A 0A  22 20 21 21  ‚M.,.+/ü...." !!
0010: 0F 03 77 67  01 7F 00 00  00 00 00 00  00 80 CC CC  ..wg........€ÌÌ
0020: 91 01 DD DD  00 00 00 00  00 00 00 00  00 00 00 00  ‘.ÝÝ............
PMIC>D (burst read)
0000: 82 4D 07 2C  07 2B 2F FC  07 07 0A 0A  22 20 21 21  ‚M.,.+/ü...." !!
0010: 0F 03 77 67  01 7F 00 00  00 00 00 00  00 80 CC CC  ..wg........€ÌÌ
0020: 91 01 DD DD  00 00 00 00  00 00 00 00  00 00 00 00  ‘.ÝÝ............

Two salea files are in attached PMIC.ZIP

PMIC.ZIP 

What is wrong? Is this a mistake in manual or a bug in the chip? 

I hope the chip is OK. I have seen LP8733: LP87334 Buck Converter Status on I2C - Power management forum - Power management - TI E2E support forums blaming some bit explanation in same manual...

Regards, Kalman

  • 0
    TI__Mastermind 18107 points

    Hi Kalman, 

    Thank you for bringing this to attention. 

    It seems that the auto-increment feature for reading was not thoroughly tested at the time when the document was created, and hence we could not guarantee its support. 

    We did not originally intend the device to be used for burst reads, so doing so is not recommended.
    The burst read does appear to have the same results as the one-by-one reads, but please be aware that using the auto-increment for read operations is not validated by TI.
    Doing so may be at your own risk and discretion, and we cannot guarantee it will always work.  

    Until we do our own testing and validation of this function, we may not update the datasheet. 

    Best Regards, 
    Sarah

  • +1
    Intellectual 580 points

    Hi Sarah,

    thanks for clarification, it solved my problem. I will use single register access in my application.

    I hope the silicon is OK and I do not really understand why is the auto-increment feature limited to write operation?

    Regards, Kalman