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DS90UB903Q-Q1: The mcu on the 903 side can not access the 904's registers by I2C.

Part Number: DS90UB903Q-Q1

Hi, team 

I am using the 903/904 serdes pair to transfer image.

I have the following  troubles:

1.The 903's MODE=H and 904's MODE=L, according to the D/S, the mcu on the 903 side should can access the registers of 903 and 904, but it can not access the 904's registers.

the default i2c address is 0x58 for 903 and 0x60 for 904, and I2C pass through is enable by default !

2. for  the 0x0C register of 903,  according to the d/s, the LINK DETECT=1 when Cable link detected, but in fact LINK DETECT=0 when cable is linked and is 1 when cable not linked, the datasheet is wrong or the IC is in wrong status?

3. the 903's PCLK_AUTO = 1 by default, when no valid pclk input to the 903, the 903 output internal 25 MHz to 904, but when 903's MODE=0, 904 can not detect the 25MHZ pclk, when when 903's MODE=1, 904 can detect and output 25mhz pclk

Thank you 

Best regards

  • how many boards do you have these issues? can the link be created?
    we'll check it according to the d/s for details later.

    regards,
    Steven
  • about 20 pieces have these issues!
  • the link can be created!
  • 1.The 903's MODE=H and 904's MODE=L, according to the D/S, the mcu on the 903 side should can access the registers of 903 and 904, but it can not access the 904's registers.
    the default i2c address is 0x58 for 903 and 0x60 for 904, and I2C pass through is enable by default !
    TI: pls refer to d/s: To configure the devices for display mode operation, set the Serializer MODE pin to High and the Deserializer MODE pin to Low. Before initiating any I2C commands, the Serializer needs to be programmed with the target slave device address and Serializer device address. DES_DEV_ID Register 0x06h sets the Deserializer device
    address and SLAVE_DEV_ID register 0x7h sets the remote target slave address. If the I2C slave address
    matches any of registers values, the I2C slave will acknowledge the transaction allowing read or write to target
    device. Note: In Display mode operation, registers 0x08h~0x17h on Deserializer must be reset to 0x00.

    2. for the 0x0C register of 903, according to the d/s, the LINK DETECT=1 when Cable link detected, but in fact LINK DETECT=0 when cable is linked and is 1 when cable not linked, the datasheet is wrong or the IC is in wrong status?
    TI: it could have noise in the high speed pin in your system.

    3. the 903's PCLK_AUTO = 1 by default, when no valid pclk input to the 903, the 903 output internal 25 MHz to 904, but when 903's MODE=0, 904 can not detect the 25MHZ pclk, when when 903's MODE=1, 904 can detect and output 25mhz pclk
    TI: what is "904 can't detect 25M PCLK"? pls be detailed.


    Regards,
    Steven
  • Hi, thanks for your help.
    1. the registers' values you mentioned are all in right status
    2. the the 904 is locked and can receive the image from 903, the image transfer is okay!, so there should not be noise!
    3. when 903's mode=L, the 903 can not output the internal 25MHZ even when no valid pclk detected!