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ADV7842-7511 8-bit ddr mode

Question asked by Pittiplatsch on Dec 16, 2016
Latest reply on Dec 19, 2016 by Pittiplatsch



I have the ADV7842-7511 Eval Board and I'm trying to run the repeater in 4:2:2 8-bit ddr mode. The output video is somehow recognizable, but it is slightly burred and flickering and the colors are wrong.


My setup is as following:


- HDMI source signal to ADV7842 HDMI Port A (J8)


- ADV7842 to ADV7511 video bus headers D_RX[23:16] to D_TX[23:16] which corresponds J2 25-26, 27-28, 29-30, 31-32, 33-34, 35-36 and J3 1-2, 3-4, all other PINs of J2 and J3 are disconnected


- ADV7511 HDMI output J13 to generic display device


After start-up I change following registers:



- OP_FORMAT_SELECT R0x03 to '20': 8-bit 4:2:2  DDR mode   *edit: 32 = 20hex

- OP_CH_SEL R0x04 to '3': P[35:24] V/R, P[23:12] Y/G, P[11:0] U/CrCb/B      

- everything else as default



- INPUT ID R0x15 to '6': YCbCr 4:2:2 (12, 10, or 8 bits) DDR with Separate Syncs

- COLOR DEPTH R0x16[5:4] to '11': 8 bits

- INPUT STYLE R0x16[3:2] to '11': Style 3

- DATA INPUT EDGE R0x16[1] to '1': Rising Edge 

- VIDEO INPUT JUSTIFICATION R0x48[4:3] to '10': 2 Left Justified

- everything else as default


I also tried some other settings, but with the above I get the best result so far... Am I missing something?


Regards and thanks for help!