DS90UB940-Q1: How to access serializer's registers from deserializer side by I2C ?

Angus

Part Number: DS90UB940-Q1

Hi, team

I use DS90UB940 and DS90UB949 pair to transmit video.

And now I can access the DS90UB940's registers via I2C from DS90UB949 side, but I can't access the DS90UB949 's registers from DS90UB940 side.

over 7 years ago

0 Vijaya Ceekala over 7 years ago

TI__Intellectual 2930 points

hello Angus

Which side is your controller located? What is the state of 949 part when you are trying to access this?

0 Angus over 7 years ago in reply to Vijaya Ceekala

Intellectual 370 points

Hello Vijaya, thanks for help.
I use the DS90UB949 EVM to test DS90UB940 mounted on our customized board.
the 949 is in the default state. I can access the 940 and 949 registers from the LaunchPad, but I can not access 949 registers from 940 side using I2.

0 Cera Wei over 7 years ago in reply to Angus

TI__Intellectual 2010 points

Hello Angus,

How did you read the 949 register? Use the lauchpad?

Could you check the following setups:
1. Check 949 ID on Reg.0x07 of 940 to make sure the ID you used is right.
2. Check Reg.0x06 on 940 to see if there's forward channel sequence error.
3. Do BIST to see if there's any errors.
4. Check the mode of 949 and 940.

Best regards,
Cera

0 Angus over 7 years ago in reply to Cera Wei

Intellectual 370 points

Hello Cera, thanks for help
I know why I can not access 949 registers, because the I2C PASS-THROUGH on Register 03 of 940 is disabled by default.
I enable this bit and it works well.

0 Angus over 7 years ago in reply to Cera Wei

Intellectual 370 points

Hello cera , can you help me in another case
e2e.ti.com/.../660751

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DS90UB940-Q1: How to access serializer's registers from deserializer side by I2C ?