DS90UB926Q-Q1: Register value is different from defaul

Hi Ishiwata,

The register 0x22 is loaded from the serialzier so if there is a serializer connected, the value will change.

Register 0xF2 =0x42 is correct since this is a UB device.  0x42 matches the letter B. 

I will look into the rest.

Best Regards,

Charley Cai

Hi Charley,

Thank you for your reply.
Please continue to check other registers.
I am looking forward to your confirmation.

Best Regards,
Ishiwata

Hi Ishiwata,

Would you be able to provide the top marking of the IC?

Best Regards,

Charley Cai

Hi Charley,

Sorry for the late reply.　Japan was a holiday.

The contents are as follows, but please tell me the background and reason.

　>Would you be able to provide the top marking of the IC?

We need to explain the reason to the customer to confirm top marking.

Best Regards,
Ishiwata

Hi Ishiwata,

The Top marking will help us confirm the production date of the 926 device.

Best Regards,

Charley Cai

Hi Charley,

I know top marking is the date of manufacture.

For example, there are reports that similar registers have changed, and you would like to confirm the manufacturing date.
Is there such a reason?

Or do not know the cause, but want to check the manufacturing date for the time being?

Best Regards,
Ishiwata

Hi Charley,

I confirmed the top marking.
It will be as follows.

　96ANETUG3
　UB926QSQ

Please check.

Best Regards,
Ishiwata

Hi Ishiwata,

For register 0x05, 0x1E is the correct value,

For register 0x44, this register is for adaptive EQ and will change depends on the EQ setting. 

For register 0x01, the default should be 0x04 instead of 0x0.

Would the customer be able to try doing a digital reset including registers to see if 0x1 returns to 0x04?

Best Regards,

Charley Cai

Hi Charley,

Thank you for your reply.
Register 0x01 prompts the customer again for confirmation.

The check results are summarized below. Is it OK?

Although there was no description about the confirmation of the top marking, does it mean that there was no particular abnormality?

Best Regards,
Ishiwata

Hi Ishiwata,

Yes, we need some confirmation from the customer about register 0x01.

The summarized results are ok.

The top marking didn't show anything abnormal.

Best Regards,

Charley Cai

Hi Charley,

Customer tried that turned on / off the power and confirmed Reset [0x01].
Also performed a digital reset. The result was 0x00.

Do you have Possible causes？

Best Regards,
Ishiwata

Hi Ishiwata,

I was not able to find any clue on why this register is different. We were able to check some 926 devices we have here and the register read matches datasheet.

Do they see this on multiple devices or just a single device?

The customer can send this device back to TI for verification.

On a functional level, this register can be overwritten to desired setting after device power on.

Best Regards,

Charley Cai

Hi Charley,

Thank you for your reply and support.
I confirmed the customer's evaluation status.
The DS90UB925Q-Q1 - DS90UB926Q-Q1 is working properly with the designed board.
It is also locked and the image is displayed correctly.
There was no problem in the operation and only the register was different from the data sheet, so Customer made an inquiry to us.

Currently, if the register of 0x00 is 0x00, Back Channel is disabled, so it is not locked and does not operate normally.
However, because it is operating as a reality, Back Channel is operating.

>"Do they see this on multiple devices or just a single device?"
The customer is evaluating only one product, so they will check several more in the future.
Customer will check that they see this on multiple devices or just a single device.

Best Regards,
Ishiwata