This FAQ was generated from the following discussion: Black line on the Output from the ADV7282-M
Can you receive my message?
I found a phenomenon as belows:
I wrote 0xD7 to User Map register 0x04 when setting register of adv7282m chip in the initialization phase,
I can see a black line at the bottom of image,At this point I have to re-write 0x57 to User Map register 0x04,
then Black line disappears.
So I added the action(wrote 0x57 to 0x04 register) at the end of initialization,but issue is still there.
I am very confused and do not know how to solve.
Sorry for getting back to you later.My reply to you as belows:
1.I confirmed again that ACE was disabled.
2.single ended CVBS.
3.It is normal when connecting analog video directly to television.
4.I used two different analog video to test,it is the same result.
5.The issue can't occur in free-run mode(color bar or blue screen).
6.Backed device is based on Qualcomm platform(often used as a phone platform).
7.I used the I2P deinterlacer in the ADV7282-M .
Dear Yuanyuan guo,
I have not seen an issue like this before. Could you try the following to try and help me diagnose the problem.
1) Could you please double check that ACE is disabled.
ACE is enabled by writing 0x80 to User Sub Map 2 register 0x80. ACE is disabled by writing 0x00 to User Sub Map 2 register 0x80. See Adaptive contrast enhancement section of ADV728x hardware manual for more information.
2) What analog video input type are you using e.g. Differential CVBS, single ended CVBS, S-video etc?
3) Could you feed the analog video directly to a television to see if the issue is still there.
4) Could you use a different analog video source e.g. DVD player.
5) Could you force free-run mode. Set User map Register 0x0C bit to 1. This will force the ADV7282-M to output a blue screen output. A number of different test patterns are also possible. See Free Run Operation Section of ADV728x hardware manual for more information.
Does the issue still occur in free-run mode?
6) What backed device are you feeding the MIPI CSI-2 output from the ADV7282-M into?
7) Are you using the I2P deinterlacer in the ADV7282-M or are you deinterlacing the video in the backend device?
Analog Devices Inc.