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(ADV7281A)MIPI sequence when our customer change AIN channel.

Question asked by donadona999s on Feb 19, 2018
Latest reply on Feb 26, 2018 by donadona999s

Hi!

 

I have a question about ADV7281A.

MIPI CSI-2 Tx power up/down sequence of ADV7282-M. 

At this thread, this is written.

**************************************************************************************************************

2) If changing video mode [e.g. changing from differential CVBS to single ended CVBS] do a software reset

    of the ADV728x by writing 0x80 to User Map register 0x0F. Then perform ADI recommended script.

     2b) If you are not changing video mode [e.g. switching from single ended CVBS on Ain1 to 

           single ended CVBS on Ain2] then a software reset of the ADV728x is not needed.

           Also you can simply change the INSEL register instead of running a script.

     2c)  I advise using the Fast switch script to minimize the ADV728x lock time to video sources.

**************************************************************************************************************

I was reading this discussion and I think ADV7281A is same.

But I want to confirm few things.

 

Our customer will use ADV7281A-M for automotive application.

They will use input two differential CVBS input for rear and front camera.

 

Question No.1)

Does the past thread mean if our customer want to change input channel, they don't need software reset and just changing INSEL is enough?

 

Question No.2)

Should our customer power down ADV7281A-M MIPI output and power up after they change INSEL?

Or can they change INSEL while outputting MIPI (Not power down and up the MIPI output)?

 

Question No.3)

If our customer can change INSEL while outputting MIPI, what will happen to the MIPI waveform?

Since it is not synchronized between analog input channels, I think that the waveform is distorted.

So I think for Question No.2, it would be better to power down and up when they change INSEL.

 

Best regards
Kawa

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