DS90UB954-Q1EVM: Queries Regarding STP Mode in DS90UB953-Q1 EVM Connected with DS90UB954-Q1 EVM.

Hi,

Have you measured the supply voltage on all VDDxx pins on the SER and DES to make sure the devices are operating?

Can you make sure PDB pins are powered up on both sides?

Can you provide schematics for both sides, SER and DES?

Also, are you applying any code/ register settings to any of the devices? If yes, can you share?

Hi TI,

1. PASS and LOCK are successfully established, and we are able to communicate with both the    serializer and the sensor.

   2.The register configurations are as follows:

    Deserializer:

      {reg   => value}

      {0x01 => 0x02}
      {0x0C => 0x01}
      {0x09 => 0x11} 
      {0x0A => 0x06} 
      {0x0B => 0x0C} 
      {0x1F => 0x02}           
      {0x20 => 0x20} 
      {0x33 => 0x03}      
      {0x42 => 0x71}
      {0x4C => 0x01}
      {0x58 => 0xDE}
      {0x5C => 0x18}
      {0x5D => 0x6C}
      {0x65 => 0x36}            
      {0x7C => 0x00}

    Serializer: 

      {reg   => value}
  {0x01 => 0x02}
      {0x02 => 0x73}
      {0x0A => 0x11} 
  {0x0B => 0x06} 
  {0x0C => 0x0B}

3. Schematics
   
      Serializer:                  

                          
      Deserializer:

          

    4.Both the serializer and deserializer are kept in synchronous mode.
    

Hi Ti,

   This is a follow-up message regarding the queries I shared earlier. Kindly let me know if you need any additional information or clarification from my side.

Hello,

To confirm, the serializer and deserializer have stable lock and are operating without errors? The issue is that the camera is not streaming to the serializer? Is any data being detected by the SoC?

Can you verify if the camera is streaming by reading registers 0x61 - 0x63 of the serializer and registers 0x73 - 0x76 of the deserializer?

To verify that there is not a hardware issue, can you enable the pattern generator on the devices? Enable the pattern generator on the deserializer first, this will test the hardware connection between the deserializer and the SoC. If the SoC is able to receive the pattern, then test with the pattern generator on the serializer instead.

Hi Ti,
   The camera is streaming, but the stream is intermittent. We are currently observing bandwidth issues.

Hello,

Are you seeing bandwidth issues with the serializer or deserializer? To decrease the data payload of the camera, the fps and/or resolution can be decreased.

Hi Ti,

   Currently, the per-lane data load is approximately 246 Mbps. The camera resolution is 2104×1560 at 30 fps.

Hello,

Can you please describe the behavior being seen? Is corrupted data received, is no data received, or is there a black screen? How are you determining that there is a bandwidth issue? Are any errors being reported by the SoC, serializer, or deserializer? If so, what errors are being reported and how frequently are the errors seen?

Hi Ti,

    We are observing a pinkish glitch in the video stream whenever the cable is moved. When the cable remains stationary, the issue does not occur. So far, we have not encountered any errors from the SoC.

Could you please help us understand the possible causes of this behaviour? Additionally, could you suggest which parameters or factors we should investigate to help resolve the issue?

We are also attaching the AEQ margin test results for the 1.524-meter cable we are using, obtained using the ALP tool.

Hello,

Why do you suspect this is a bandwidth issue? The cable's movement does not impact the data payload. The payload is sent by the camera and would not be impacted by cable movement. If only moving the cable causes issues, this indicates that the issue is likely the cable or the cable connections. A video glitch should result in a detectable error, are you sure no errors are being detected? 

Hi Ti,
       We are now able to get the streaming to work, but only with specific types of Shielded Twisted Pair cables. Could you let us know how to stream regardless of the cable type we are using?

There is no configuration within the device for cables. If certain cables do not work, that means there is an issue with those cables, such as introducing loss on the channel.