DS90UB933-Q1: DS90UB933 I2C getting "Nak" when streaming is working

Hi Ariel, 

Can you please provide more information on the set up being used here? Is the DS90UB933 and DS90UB934 EVMs being used or is this a custom design? If this is a custom design would you be able to share the schematics? 

It was stated the there is a NAK from time to time - what is the occurrence rate and does this happen during a specific transaction? 

Best,

Zoe

Serialize - drawing

Des :

System is working fine most of the time , meaning:

Host can "talk" through the I2C channel and get response .- reading data from slave.

the lock bit is "on" and the image are 100% ok.- no miss line , pixels or noise.

when the PSI bus is working , From time to time the slave not responding  and  "NAK" is generated from slave

it never happen when the PSI is off ( Pclock  not working and Lock is off)

Does the PSI and the I2C channels are somehow connected and interference each other ?

using an  oscilloscope We can't see noise on the I2C bus such as crosstalk etc' 

Any help will be appreciated 

Ariel

Hi Ariel, 

Appreciate the further clarification. Would you be able to do this testing with only the 933 and 934 connected? The 933 and 934 should be able to lock with no input PCLK. This would only be reflected in register 0x4D.

Is the NAK on a transaction to a specific device? 

Best,

Zoe