Any issues using CYUSB2014 for NTSC/PAL monochrome video using BT.656?

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Anonymous
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I'm considering the CYUSB2014 for a USB 2.0 application where I'll be receiving analog video.  I'd like to use a simple Video decoder IC like a T.I. TVP5150AM1, which puts out 8-bit ITU-R BT.656 codes as well as horizontal and vertical syncs and active video signals.  The data clock is 27 MHz with two clocks per pixel during 720 active pixels (1440 bytes) per line.  I only really need monochrome images, so I would like to know if it is possible to program the GPIF II to accept only every other byte during the active video.  Otherwise I may need to go to a more advanced chip like the T.I. TVP5146M2, which puts out separate Y and CrCb buses at 13.5 MHz.  This is a very space-limited application so I'd prefer to use the smaller IC if possible.  Are there any gotchas I'm missing if I go ahead with the ITU-R BT.656 style decoder with 8-bit bus at 27 MHz?  I'm worried that if I can't filer out the CrCb bytes of the line I will lose data using USB 2.0.  The line-average data rate for this chip in color would be 22.66 MB/s, which is pretty close to the raw bandwidth of the USB at high speed.  Filtering out the color components would get it down to a more comfortable 11.33 MB/s (line average).  I don't have the option to use USB 3.0 in this application.

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2 Replies
Anonymous
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Hi,

   

Yes, it is indeed possible to program the GPIF II to accept only every alternate byte.  

   

Regards

   

Dhritiman

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Anonymous
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Thank you.  I think I will probably try to generate the required state logic for the GPIF II before I commit to a PC layout, but I just wanted to be sure I wasn't wasting my time trying.  This looks like a very capable and flexible part, but it's completely new to me.  I'm used to doing a lot of glue logic in CPLD or FPGA and then using a more standardized interface for other chips.

   

Regards,

   

Gabor

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