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ADV7842 Component Mode 720p is too dark

Question asked by LShields on Aug 7, 2015
Latest reply on Aug 10, 2015 by DominicB

Our ADV7842 is using auto graphics mode to detect and run in several different modes.  We have component mode working, but 720p and 1080p modes appear too dark.  480p, on the other hand are not dark.  The second interesting fact is if we change PRIM_MODE to 0x01 and VIDMODE=0x13, the 720p looks proper with the right brightness.  Is there some way to make the auto graphics work between all 3 modes without changing PRIM_MODE/VIDMODE?

 

Here is a dump of the current registers:

 

i2cdump -y 2 0x20 (IO)

No size specified (using byte-data access)

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef

00: 07 02 82 82 42 28 a6 00 14 00 90 44 40 1e 0f 1e    ????B(?.?.?D@???

10: 00 00 00 e3 19 80 c6 72 34 80 02 00 00 00 00 00    ...????r4??.....

20: f1 01 00 03 00 00 00 00 00 00 00 00 00 00 00 00    ??.?............

30: 88 00 00 40 00 00 00 00 00 00 00 00 00 00 00 00    ?..@............

40: 20 30 94 00 00 00 00 04 00 00 00 00 00 00 00 00     0?....?........

50: 00 04 00 00 00 00 05 00 00 00 00 b5 00 00 00 00    .?....?....?....

60: 00 00 00 00 00 40 00 00 00 00 00 00 00 00 00 01    .....@.........?

70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

80: 00 00 00 40 00 00 00 00 00 00 00 00 00 00 00 00    ...@............

90: 00 00 00 00 00 00 00 00 00 00 00 00 0c 00 00 00    ............?...

a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

b0: 00 00 00 00 00 00 00 43 e0 00 00 00 00 00 00 00    .......C?.......

c0: 00 0e 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .?..............

d0: 00 0b 07 00 f0 0f 00 00 2d 15 f1 5f 40 00 00 00    .??.??..-??_@...

e0: 00 00 04 00 01 00 00 00 04 00 20 12 00 00 00 00    ..?.?...?. ?....

f0: 00 90 94 84 80 7c 00 00 4c 64 6c 68 00 44 48 00    .????|..Ldlh.DH.

 

i2cdump -y 2 0x22 (CP)

No size specified (using byte-data access)

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef

00: 00 00 00 00 00 00 00 00 00 02 00 40 00 00 00 00    .........?.@....

10: 08 00 00 00 00 01 00 00 00 00 00 20 00 00 00 00    ?....?..... ....

20: 20 00 00 00 00 00 01 2c 06 30 00 00 00 00 00 00     .....?,?0......

30: 00 00 00 00 00 00 00 00 00 00 80 80 00 00 00 00    ..........??....

40: 5c 02 3b d4 03 33 00 02 7c 93 df 2a ed 07 4a 83    \?;??3.?|??*??J?

50: c0 00 40 00 00 00 00 08 00 00 00 00 01 00 00 00    ?.@....?....?...

60: 00 00 20 00 00 00 00 00 f0 04 00 00 00 00 00 00    .. .....??......

70: 00 00 00 ea 8a a2 a8 ff ff ff ff 05 c0 00 00 00    ...????....??...

80: 00 c0 04 00 0c 0b 0b 00 00 00 20 40 00 00 00 40    .??.???... @...@

90: 00 00 00 00 00 00 00 f0 00 00 00 00 00 00 00 00    .......?........

a0: 00 00 00 00 00 2e a0 1a 00 00 00 2e e0 00 60 00    ......??....?.`.

b0: 00 3f ff 00 00 81 00 00 10 5f 01 00 00 18 00 16    .?...?..?_?..?.?

c0: 00 80 80 39 44 91 00 00 00 2c 00 60 27 2f c3 00    .??9D?...,.`'/?.

d0: 00 00 00 00 00 00 00 00 00 00 00 19 64 12 c5 78    ...........?d??x

e0: d0 00 33 10 4c 4b 00 03 ff 01 01 08 00 14 42 14    ?.3?LK.?.???.?B?

f0: a8 40 04 d4 00 00 00 15 03 33 86 52 02 ee 03 08    ?@??...??3?R????

 

i2cdump -y 2 0x26 (AFE)

No size specified (using byte-data access)

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef

00: 80 00 40 00 00 07 20 1f 00 00 00 00 1f 13 00 90    ?.@..? ?....??.?

10: 30 82 63 00 00 0a 98 00 00 00 00 00 00 6d 6d 6d    0?c..??......mmm

20: 6d 6d 6d 6d 6d 00 08 ff ff 00 00 00 00 00 00 00    mmmmm.?.........

30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

80: 80 20 80 02 02 0a 0a 0a f8 66 fc 13 f8 15 de 86    ? ???????f??????

90: c1 91 82 70 00 00 00 00 ff 0f ff 00 00 00 00 00    ???p.....?......

a0: 00 02 02 ff ff ff f8 66 fc 13 f8 15 de 86 c1 91    .??...?f????????

b0: 82 70 ff 0f ff 01 00 00 00 00 00 00 00 6f 02 fa    ?p.?.?.......o??

c0: c0 98 80 00 30 02 03 00 00 00 00 00 40 0a 96 00    ???.0??.....@??.

d0: 25 23 e1 ae ff cc 05 00 00 1b 04 00 00 00 00 00    %#??.??..??.....

e0: 00 00 00 00 06 06 00 00 00 00 00 00 00 00 00 00    ....??..........

f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

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