• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 22 subscribers
  • Views 349 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.

LMK05028: Post-Divide Register Validation

RanjithKumar T R
Prodigy 60 points

Part Number: LMK05028

Hi,

According to

https://www.ti.com/lit/ds/snas724a/snas724a.pdf

https://www.ti.com/lit/ug/snau233/snau233.pdf

We are trying to implement DCO frequency stepsize to our codebase. But while reading the Post-Divide Value(PLL1_P1) register we get the value as 0x00.

The expected value is 3 - 8, 0xa, and 0xc but we get only 0x00.

P1PLLy = PLLy primary post-divide value (4 to 9, 11, 13)(Note: A RESET is required after changing Divider values) 
3h = 4,4h = 5,5h = 6,6h = 7,7h = 8,8h = 9,Ah = 11,Ch = 13
Could you please tell us how to get Post-Divide value?
Thanks 
Ranjith
  • 0
    TI__Expert 6140 points

    Hello,

    Is the device actually locked and outputting? If so, the post divider cannot be zero.

    Are you reading the correct register? R92 [7:4] are PLL1_P2 and R92 [3:0] are PLL1_P1.

    Can you read registers to confirm there are no issues with I2C read? Note that the register address in LMK05028 uses 2 bytes, register address high as well as register address low - see page 65 of the datasheet section 9.5.2.

    Regards,

    Amin

  • 0 in reply to Amin Eshraghi
    Prodigy 60 points

    Hi,

    The Ti is locked and outputted. We have attached the "status and interrupt" snapshot for your reference.

    We are using i2c_smbus_write_byte_data and i2c_smbus_read_byte_data linux API to R/W the offset. Post_divide register read via TicsPro is 0x33 (snapshot attached) but i2cdump in kernel gives 0x00.
    root@stratix10:~# i2cdump 1 0x60

    No size specified (using byte-data access)

    WARNING! This program can confuse your I2C bus, cause data loss and worse!

    I will probe file /dev/i2c-1, address 0x60, mode byte

    Continue? [Y/n] y
         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
    00: 10 0b 96 00 06 00 00 00 00 00 96 00 00 00 00 00    ???.?.....?.....
    10: 00 00 00 82 00 00 00 00 00 00 00 00 00 00 00 00    ...?............
    20: 00 05 00 0f 00 00 00 00 00 00 80 00 00 00 00 00    .?.?......?.....
    30: 00 6a 00 00 00 00 00 00 00 01 00 00 00 00 00 00    .j.......?......
    40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
    50: 00 02 09 00 00 00 00 00 00 00 00 c4 00 00 00 00    .??........?....
    60: 00 03 0f 00 00 00 00 00 00 00 01 44 00 00 00 00    .??.......?D....
    70: 00 00 33 00 00 00 00 00 00 b2 00 00 00 00 00 00    ..3......?......
    80: 00 00 96 01 00 00 00 00 00 00 00 00 00 00 00 00    ..??............
    90: 00 08 00 00 00 00 00 00 00 01 00 00 00 00 00 00    .?.......?......
    a0: 00 00 00 00 00 00 00 00 00 00 00 44 00 00 00 00    ...........D....
    b0: 00 a3 00 00 00 00 00 00 00 80 0a 00 00 00 00 00    .?.......??.....
    c0: 00 00 00 00 00 00 00 00 00 1c 8b 00 00 00 00 00    .........??.....
    d0: 00 00 08 00 00 00 00 00 00 17 05 00 00 00 00 00    ..?......??.....
    e0: 00 02 00 00 00 00 00 00 00 02 01 01 00 00 00 00    .?.......???....
    f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
    root@stratix10:~#
    Kindly provide your suggestions on this.
    Thanks,
    Ranjith
  • 0 in reply to RanjithKumar T R
    TI__Expert 6140 points

    Hello Ranjith,

    So readback via TICSpro is showing expected values correct?

    I'm not an expert on the tool you're using here, I can see if anyone else in the group is to support. But this doesn't seem to be related to LMK05208 as TICSpro readback value is correct and device is functioning.

    Regards,

    Amin