• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 34 subscribers
  • Views 264 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.

DS90UB949A-Q1: Communication with remote DES

Amy Luo
Expert 6895 points
Part Number: DS90UB949A-Q1


Hi team,

The customer uses the mcu+949->948+display scenario. The DES ID of 948 can be detected, but the 948 7-bit address cannot be used to get the 948 register value via I2C, what is the reason?

The address and description of the DES ALIAS register were not found in the 949 datasheet. The datasheet description of the slave alias[0] appears to be for remote slave and not for 948(remote Des), and when slave alias[0] is configured to the same value as DES ID, the 948 register is still inaccessible

Best Regards,

Amy Luo

  • 0
    TI__Guru 66880 points

    Hi Amy, 

    Can you provide a register dump of the SER to see what values are in the I2C configuration registers, DES address/alias, etc?

    Regards, 

    Logan

  • 0 in reply to Logan Cummins
    TI__Expert 6895 points

    Hi Logan,

    The value of the 949 register is in the picture,

    Where 0x6 is des ID,

    0x8 is slave alias[0],

    0x3 is configured with i2C pass through,

    0x17 is configured with i2C pass all,

    According to the datasheet, after configuring both pass through and pass all, it is also possible to communicate with 948 without configuring des alias, but it is not, and the des alias register does not exist in the 949 register map

    Best Regards,

    Amy Luo

  • 0 in reply to Amy Luo
    TI__Guru 66880 points

    Hi Amy, 

    Thanks for the info. 

    Can you share what address you are trying to write/read to? Can you share a waveform/logic analyzer of a command? 

    Per register 0x06, the DES ID is 0x58. 

    Can you verify that the wrong address isn't being used?

    Regards, 

    Logan

  • 0 in reply to Logan Cummins
    TI__Expert 6895 points

    Hi Logan,

    The address used by the customer when writing 948 is 0x58 and 0x59 when reading.

    The I2C currently used by the customer is an I2C simulated by software. I don't know whether it is caused by this. Will this have any impact on the communication here?

    Best Regards,

    Amy Luo

  • 0 in reply to Amy Luo
    TI__Guru 66880 points

    Hi Amy, 

    Amy Luo said:
    The I2C currently used by the customer is an I2C simulated by software. I don't know whether it is caused by this. Will this have any impact on the communication here?

    I'm not sure I understand, what do you mean the customer is using I2C simulated by software? Can you elaborate on their set-up?

    Are they using EVMs or customer design boards? 

    Can you try reading/writing to the Deserializer directly on the deserializer board to verify you can communicate to it without the FPD-Link in between? 

    Logan