CDCE813-Q1: I2C read returns the wrong value; I2C write is invalid

Intellectual 530 points

Replies: 3

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Part Number: CDCE813-Q1

I detected CDCE813 under i2c4  which address is 0x65.

I can also read back the registers, but all values are 0x07.

And I can't override the value of any register.

[18:19:09]root@dra7xx-evm:~# i2cdetect -r -y 4
[18:19:09] 0 1 2 3 4 5 6 7 8 9 a b c d e f
[18:19:09]00: -- -- -- -- -- -- -- -- -- -- -- -- --
[18:19:09]10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
[18:19:09]20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
[18:19:09]30: 30 -- -- -- 34 -- -- -- 38 -- -- -- 3c 3d -- --
[18:19:09]40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
[18:19:09]50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
[18:19:09]60: -- -- -- -- -- 65 -- -- -- -- -- -- -- -- -- --
[18:19:09]70: -- -- -- -- -- -- -- --
[18:19:22]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x00
[18:19:22]0x07
[18:19:24]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x01
[18:19:24]0x07
[18:19:25]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x02
[18:19:25]0x07
[18:19:29]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x03
[18:19:29]0x07
[18:19:30]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x04
[18:19:30]0x07
[18:19:43]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x05
[18:19:43]0x07
[18:19:44]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x06
[18:19:44]0x07
[18:19:46]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x07
[18:19:46]0x07
[18:19:52]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x08
[18:19:52]0x07
[18:20:03]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x09
[18:20:03]0x07
[18:20:20]root@dra7xx-evm:~# i2cset -f -y 4 0x65 0x05 0x01
[18:20:25]root@dra7xx-evm:~# i2cget -f -y 4 0x65 0x05
[18:20:25]0x07

30, 34, 38, 3c and 3d are the addresses of UB934.I can use i2c4 to read and write their register values normally.

I set the  clock frequency of i2c4 to 400khz, 100khz, 40khz, 10khz.But all the results are not normal

This is the schematic of the CDCE813 part.

which  place should I modify to properly configure CDCE813?

regards,

chengbo

3 Replies

  • Hi Chengbo,

    I'll look into this and get back to you tomorrow.

    Regards,
    Hao

  • In reply to Hao Z:

    Hi Z,

    Do you know how to solve this problem?

    regards,

    chengbo

  • In reply to chengbo:

    Hi Chengbo,

    The schematic looks good to me and 0x65 is correct I2C slave address, so I think the hardware should be fine. I'm not familiar with the controller you are using. Can you start with the GUI for TI EVM? http://www.ti.com/tool/CLOCKPRO

    You can choose CDCE913, because CDCE913 and CDCE813 are same parts with difference default settings. Since you will program the device anyways, these two parts have no difference. That being said, you can also refer to the documentation for CDCE913 such as appnotes and user's guide.

    Let me know if you have any luck with ClockPro.

    Regards,
    Hao