• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 32 subscribers
  • Views 342 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB960-Q1: Line Length

Jared Becker
Genius 11845 points
Part Number: DS90UB960-Q1

Hi Team,

I am looking at registers 0x75 and 0x76 for the line length report from the 960. My camera is resolution 1280 x 800 and the output format is 8-bit. 

I am seeing values of 0x75 = 0x0C and 0x76 = 0x80. Do I combine those into one number being 0x0C80? If so, that equals 3200. Is that the correct value given the parameters above? How do I convert between the camera resolution and values in registers 0x75 and 0x76?

Thanks!

Jared

  • 0
    TI__Guru** 103215 points

    Hello Jared,

    Line length is reported in bytes, not pixels, so the number you get depends on the number of bytes per pixel for the data format. It looks like this is 2.5 bytes per pixel. What specific CSI-2 data format is this? It doesn't sound like RAW8

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    TI__Genius 11845 points

    The camera is transmitting YCbCr 4:2:2 8 bit, so does that mean that the 960 is not receiving the proper image resolution? The camera is also using ta 913 serializer.

  • 0 in reply to Jared Becker
    TI__Guru** 103215 points

    Hello Jared,

    913A is a DVP mode serializer so it has two operating modes: RAW10 or RAW12. YUV422 8 bit is a 16 bit per pixel format so it doesn't divide evenly into either of the 10/12 bit formats 913A can provide. When you use 913A to transmit YUV422 8 bit, you set 913A into RAW10 mode, and then send one pixel over two PCLK cycles, with 4 bits going unused in the 20 total bits. When you receive this data on the 960 side, you have to tell the 960 what data format to output the data as over CSI-2 so you put the code 0x1E in register 0x70 which means that 960 will output the RAW10 mode data from 913A with the YUV422 8 bit code - however the actual data output is packed with the same format as RAW10 would be packed which means 5 pixels sent for every 2 bytes (2.5bytes per pixel). 

    So 3200 is the expected number for this resolution/format/serializer combo. 

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    TI__Genius 11845 points

    Hi Casey,

    Thank you for the detailed explanation. How did you come up with writing 0x1E to register 0x70? Bits 5:0 only discuss the value of 0x2B in the datasheet..

    Thanks,

    Jared

  • +1 in reply to Jared Becker
    TI__Guru** 103215 points

    Hello Jared,

    0x1E is the CSI-2 code for YUV422 8-bit format, and 0x2B is the format code for RAW10. The formats codes are all listed in the CSI-2 standards document. Not sure that table can be shared here since TI is not the owner of the MIPI standards 

    Best Regards,

    Casey