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DS90UB964-Q1: Full HD Support at lower frame rates?

Julio Apps
Expert 3665 points
Part Number: DS90UB964-Q1
Other Parts Discussed in Thread: DS90UB933-Q1

Team,

As stated in datasheet of DS90UB964,  only support HD,   what about FHD with lower frame rate?  Example   1080p resolution at 30Hz?

  • 0
    TI__Guru** 103215 points

    Hello Julio,

    964 can support up to 6.4Gbps CSI-2 per output port. However the input image data requirement is driven by the serializer being used. 964 is compatible with DS90UB913-Q1 or DS90UB933-Q1 serializers which support up to 100MHz PCLK maximum. This is suitable for 1080p at 30Hz, but not for 1080p at 60Hz.

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    TI__Expert 3665 points

    Thanks Casey,

    So if the serializer supports the data rate, like the x953 i can support a camera  for 1080p @ 60Hz.  

    With 6.4Gbps per output port supported on hte x964 there is plenty of bandwidth for up to 3 cameras with 1080p60Hz resolution. 

    How do i make that calculation is this correct?

    12* 1920*1080*60*1.3 = 1.9Gbps X 3 cameras ~ 6Gbps

    12 is the bits per pixel, i have to verify if this is correct with the customer not sure how this is tied to a 1MP or 2MP imager.

  • 0 in reply to Julio Apps
    TI__Guru** 103215 points

    Hello Julio,

    964 can support up to 100MHz PCLK only since it is designed to link with 933/913A. 953 can support FHD 60Hz when paired with 960 which is a newer device.  

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    TI__Expert 3665 points

    Casey,

    Ok i see, so its not a data rate limitation is a PCLK clock limitation on the x964 part.  Can you confirm this, just to make sure my thought process is correct. For 1080p@30Hz ->  12*1920*1080*30*1.3 =  970.4 Mbps throughput required. Which is easily support on the x964 and you could use 1 lane on 1 CSI-2 output port to do this.

    For a 100MHz PCLK you can support data rates up to 12Gbps = 2*80*100MHz * 32/40= 12.8Gbps on the x964.

    For 1080p@60Hz -> 1.9Gbps through put is required, so if this is broken up between 2 lanes on one CSI2 Output port i should be able to support this on the x964. Or what am i missing ? I dont quite understand  what makes the diffence between the x964 and x960 even if x960 support a faster PCLK frequency.

    1.3 is 30% overhead.

  • 0 in reply to Julio Apps
    TI__Guru** 103215 points

    Julio,

    964 is designed to pair with 933/913A at speeds up to 100MHz PCLK. This means that the highest data rate you can receive from any camera is 100MHz*12 bits = 1.2Gbps of video. Then you can forward that video out of the CSI-2 ports. Even though the per lane CSI-2 speed of 964 can support up to 1.6Gbps (6.4Gbps total), each FPD-Link III video input can only support up to 1.2Gbps each. 

    So if you can't accept 1.9Gbps at the input port then of course you can not forward out 1080p60 video even though the aggregate bandwidth of the CSI-2 port is high enough to forward multiple 1.2Gbps streams.

    Best Regards,

    Casey 

  • 0 in reply to Casey McCrea
    TI__Expert 3665 points

    Got it, Thank you so much Casey!