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ADV8005 with 8-bit ITU-R BT.656 TTL input

Question asked by dlindsay on Jan 27, 2016
Latest reply on Feb 4, 2016 by dlindsay

I am trying to get a hardware design which has a ADV8005KBCZ-8B to accept a 8-bit ITU-R BT.656 YCrCb 4:2:2 (NTSC) input coming from a ADV7280WBCPZ composite video decoder. According to UG-707 ADV8005 Hardware Reference Table 89 YCbCr Input Format “8-BIT SDR 4:2:2” should be supported on TTL Input pins OSD_IN23 to OSD_IN16, along with OSD_VS, OSD_HS, OSD_CLK, and OSD_DE.

 

My design has the following connections from the ADV7280 decoder to the ADV8005:

  • OSD_IN[23:16] = P[7:0] 8-bit YCbCr from the ADV7280
  • OSD_HS is HS from ADV7280
  • OSD_VS is VS from ADV7280 (the VS/FIELD/SFL pin configured as VS)
  • OSD_DE is not connected as the ADV7280 does not provide a DE signal
  • OSD_CLK is the 27MHz LLC clock output from the ADV7280, this is of course twice the actual pixel rate. For NTSC the resolution should be 720x480i.

I cannot seem to configure the EXOSD TTL Input registers to show valid image. The ADV8005 registers are mainly in the range of 0x1B50 to 0x1B6C. I am attempting to use the embedded AV codes (SAV/EAV) that exist in the 8-bit ITU-R BT.656 video. Alternatively I can use HS and VS, but I do not have a DE input available.

 

I am using the “VSP_1.90.2REL” ADV8005 ADI API ported to run on my ARM M4 MCU. I did not see any examples for 8-bit ITU-R BT.656 in that ADV8003/8005 Eval Board software. Any recommendation for register setting would be greatly appreciated.

Thanks,

David

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