SN65DPHY440SS: Methods to confirm retimer register changes.

Rohit Bhadauria

Part Number: SN65DPHY440SS

Tool/software:

Hello,

We are using the SN65DPHY440SS retimer board with our camera module and are encountering an issue when attempting to modify its register values.

Although the I2C transactions return success and the updated register values can be read back correctly, the changes do not appear to take effect, specifically, we observe no impact on the MIPI eye diagram.

but again when we provide the power cycle to the whole system, the change is observed in MIPI eye diagram.

How can we verify whether the register values on the SN65DPHY440SS retimer board are actually changing?
Is there an alternative method to confirm register updates other than relying on changes in the MIPI eye diagram?

would appreciate any guidance you can provide on this query.

3 months ago

0 David (ASIC) Liu 3 months ago

TI__Guru**** 177101 points

Hi,

You should see the impact to the DPHY440 output signal as soon as you did the I2C write to the register. And when you power cycle the whole system, the DPHY440 I2C registers will go back to its default value.

Which lane are you measuring the eye diagram and is it in HS mode? If you write to the HSTX_VSADJ bit while the lane is in HS mode, do you see the signal amplitude change?

Thanks

David

0 Rohit Bhadauria 3 months ago in reply to David (ASIC) Liu

Prodigy 80 points

Hi David,

I want to know if is there any way to confirm the register changes through software, without checking the hardware directly.

0 David (ASIC) Liu 3 months ago in reply to Rohit Bhadauria

TI__Guru**** 177101 points

Hi,

The only way is to write, and then read the register, you should see the read value matches with the write value.

Thanks
David

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SN65DPHY440SS: Methods to confirm retimer register changes.