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DS90UH941AS-Q1: I2C access for port 1

Part Number: DS90UH941AS-Q1

Dear expert,

My setup is one UB941 connect with two UB948 in splitter mode.

Now all video display are correct. The only problem is I can only access the 1st UB948 registers at port 0 through I2C from UB941 side but cannot access the 2nd UB948 at port 1.

Two UB948 has different I2C ID (1st is 0x3C, the 2nd is 0x2C). I can see two different ID from UB941 register DES_ID_DES_ID_1 Register (Address = 0x6) with different PORT1_SEL.

Below is the code for UB941 configuration. Basically, I enabled I2C_PASS_THROUGH for GENERAL_CFG Register (Address = 0x3) with different PORT1_SEL in below code.

Could you give some guidance for me? Thanks

i2c_write 0x01 0x80

i2c_write 0x1E 0x01// enable I2C_PASS_THROUGH for port 0

i2c_write 0x03 0x9A

 

i2c_write 0x1E 0x02 // enable I2C_PASS_THROUGH for port 1

i2c_write 0x03 0x9A

 

i2c_write 0x1E 0x01

i2c_write 0x4F 0x8C

i2c_write 0x5B 0x07

i2c_write 0x56 0x80

i2c_write 0x32 0x80

i2c_write 0x33 0x07

 

i2c_write 0x40 0x04

i2c_write 0x41 0x05

i2c_write 0x42 0x30

 

i2c_write 0x01 0x00

  • Hi Ryan,

    I have taken a look at the code you have provided. Can you take a look at the descriptions and verify that everything you intended.

    Yes, you are correct. Setting I2C passthrough for both ports will allow you to communicate to both 948 attached.

    Have you tried using secondary I2C address for port 1 registers? This shoudnt affect too much in your application but I have seen some cases that will need this. 

    Very Respectfully,

    William Y.

  • William,

    Thanks for your suggestion. After enable "PORT1_I2C_EN " , the problem is solved. 

    Thanks