How to use the generic YUV interface of DM6437

if you are having the DM6437 EVM (see short description and images here: http://wiki.davincidsp.com/index.php/DM6437_EVM )

then you might have seen the boot mode switches and the signal names near to them.

they prints near to them talk about YOUT and COUT signals. you probably guess already that these wires are multiplexed - different meaning on start up and at run time.

* YOUT is a set of 8 signals that is used for the digital luminance data of the image in 16 bit bus width transfer modes.

* COUT is a set of 8 signals that is used for the digital chrominance data of the image in 16 bit bus width transfer modes.

there is further an 8 bit bus width transfer mode where the two components are interleaved by just doubling the clock rate for the digital bus.

so it should be evident that data encoding and bus width dont depend on each other.

as the responsible unit for this interface is called CCDC this name will hint you that you can connect even typical CCDC sensors to this unit.

that far i've understood that unit should work for most stock CMOS sensors (better described as APS = active pixel sensor) as well.

internally the number of bits captured from that bus is tune able in some ranges.

the most generic approach is called "raw" mode where any data source that sends "framed" data is able to connect. thus a rich set of peripherals including even a few HD video decoders and RGB video sources plus FPGA designs is able to attach here. The data troughput might go up to some 54 MHz (or a bit more) at 16 bit. Peak burst bandwidth for sending data via internal crossbars to DDR2 RAM is limited internally to some 250 (or was it 200?) MB/sec.

details can be found in the documentation of the VPSS -> VPFE -> CCDC sub unit. hints on applications and application specific designs can be found in the video & vision guide from TI, some "spry"-class document. see also the application notes; as a side note there are further DVD and Blue-Ray player sample system level designs smoewhere on TIs web pages.

  Thanks to Alexander Stohr.

    Now , we  use MT9D131 to output 8-bit YCbCr video data, and the dsp ccdc captures the 8-bit Y data after the 8-bit Cb/Cr data every clock. the sensor only provides progressive scan and has D[0...7] data output, HD, VD and PCLK, these pins are linked to the YI[0...7],HD,VD and PCLK pins of dm6437 CCDC respectively. but we see the C_FIELD/R0 signal of general YUV interface part in  the dm6437 VPFE datasheet, and don't know where this pin link. generally, this C_FIELD/R0 pin don't function for progressive YCbCr format.

   In addition, we want a demo configuration of dm6437 ccdc to receive 8-bit YCbCr progressive video from CMOS sensor. Our configuration may be incorrect. the following figure is our test image shown in TV.

 Regards

Wang Zheng guang

Shanghai,China