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Altera_Forum
Honored Contributor I
766 Views

VIP Problem with 85Hz Resolutions Frame Rate

Hi! 

 

I am relatively new to Altera and Nios2 and I am now developping a system with an ArriaV which objective is to transform VGA signal in LVDS with the ADC TVP7002. For the moment I am able to detect and correctly display in a 1920x1200 resolution monitor a large number of 60Hz input resolutions, but when I try to display 85Hz resolutions I can not output it in a high resolution (max 1400x1050). On previous posts regarding the frame rate change I have read that the frame buffer is the IP responsible for this. I have my frame buffer with the recommended configuration and enough DDR3 memory: 

 

http://www.alteraforum.com/forum/attachment.php?attachmentid=11829&stc=1  

 

The IP chain of the system is: 

 

cvi -> scaler -> frame buffer -> csc -> mixer -> cvo 

 

Do you think I should focus on the Frame Buffer or is there any other IP I should check? :confused: Have you ever had a similar problem? 

 

Thanks in advance!
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7 Replies
Altera_Forum
Honored Contributor I
19 Views

What is the frequency CVO clock and CVO data width?

Altera_Forum
Honored Contributor I
19 Views

Altera_Forum
Honored Contributor I
19 Views

Hi! The CVO paramaeters are the following: 

 

https://www.alteraforum.com/forum/attachment.php?attachmentid=11841
Altera_Forum
Honored Contributor I
19 Views

I can't see nothing on this picture, could you please make a large screenshot? In any case, you are using an external clock signal for CVO, check that its frequency is sufficient to transfer 1920x1200 pixels at 85 frames per second.

Altera_Forum
Honored Contributor I
19 Views

If you don't get anywhere, use SignalTap to monitor underflow/empty status in the FIFO's in both the VFB and CVO.

Altera_Forum
Honored Contributor I
19 Views

Hi! Sorry for the Image Size, the following are bigger: 

 

http://www.alteraforum.com/forum/attachment.php?attachmentid=11849&stc=1  

 

http://www.alteraforum.com/forum/attachment.php?attachmentid=11850&stc=1  

 

Anyway the CVO is meant to work at 60Hz because of the Screen refresh rate (And it does with small NATIVE resolutions). The Frame Buffer is the IP responsible of changing the Frame Rate from 85Hz to 60Hz.
Altera_Forum
Honored Contributor I
19 Views

Sorry for my misunderstanding. I thought you want to change output frame rate to 85 fps. Try to increase Frame Buffer burst length. Do you have any other masters on DDR?

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