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ADV7919 undocumented registers

Question asked by s.gansen on Oct 14, 2016
Latest reply on Oct 21, 2016 by s.gansen

Hello,

 

I'm currently debugging a product using the ADV7919 to receive HDMI and forward it to configurable logic. Under certain circumstances (elevated temperature combined with at least one change in resolution) we are able to reproduce stability issues. This only happens with an Intel HD4400 HDMI source. If we start our device in cold (20°C) state and do not change the resolution (constant 1920x1200), we have stable video.

 

For debugging we've compared all registers for the case of stable and for the error case. These are the differences:

 

Range

Address

Register Name

Content stable video

Content video disturbances

IO

0xD3

?

0x90

0x40

IO

0xD4

?

0x00

0x39

IO

0xD6

?

0x70

0x90

HDMI

0x1D

REGISTER_1DH ?

0x09

0x0C

HDMI

0x80

?

0x0E

0x24

HDMI

0x89

?

0x0A

0x0C

HDMI

0xFE

?

0x00

0x01

HDMI

0XFF

?

0x00

0x11

CP

0xB3

SYNC_DET_CNTRL

_CH1_RB_5

0x0F

0x10

 

As you can see, most registers are not described by the software manual. We are wondering whether / hoping that you could give us further information regarding these registers. Maybe we can get a hint pointing at the source of our video issues.

 

Regards
Simon Gansen
Dev. Engineer Hardware

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