AnsweredAssumed Answered

[ADV7181D] The transition time to Free Run mode.

Question asked by Tamu on Jul 8, 2015
Latest reply on Oct 13, 2015 by Tamu

Hello,

 

I have questions about the time for outputting Free Run blue screen image from ADV7181D.

 

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Question 1:
When we change INSEL bits from CVBS input to invalid video signal, the display becomes from CVBS image to Free Run blue screen.
The time from INSEL bits changing to Free Run blue screen displaying takes about 1.2 seconds.
In detail, I change the INSEL bits, then I can see black image first. After about 1.2 seconds, I can see Free Run blue screen.
How long is the maximum time from changing the INSEL bits (from CVBS input to no input) to outputting Free Run blue screen?

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Question 2:
Why the time takes about 1.2ms?

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Question 3:
Can we shorten the time?
If the time can be shorter, please tell me the method for that.

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Question 4:
Could you tell me required conditions for FREE_RUN_ACT(0x13[4]) = 1(Free Run Active) ?

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I had tried to confirm this on the evaluation board.
I use attached script. The input and output are CVBS.
I tried the evaluation as following order:

1. I write the script. I can see the CVBS correctly.
2. I change INSEL bits. (For example, from "1011" to "1010" etc.)

Then, I can see black image first. After that, I can see Free Run blue screen after about 1.2 seconds.
If you need your evaluation, please use the attached script.

 

Thank you!
Best regards.

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