VDMA delay between frames

[berker_atel]

Hi,

I configured VDMA as Fsycn=None and Lockgen=Master. Also video parameters:

HSIZE=200byte

STRIDE=200byte

VSIZE=4line

FrameCount=3

How can i control delay between frames? Or should i change Fsync to tuser similar options for control it.  

Second question: When 8bit AXIS is used, there is no delay between lines. You can see low level tvalid signal in the figure. But with 16bit AXIS, there is a 2-3 clocks delay. Why? How can i remove this delay? 

Thanks

[florentw]

HI @berker_atel 

I am not sure if you can improve this. If you check the figure 2-1 in pg020 you will see that there is a delay between 2 frames.

Is there a reason why you need to change this? In nost video system you have the blanking period on the native interface so this delay is not much and won't be seen at the output

Regards

[aoifem]

Ho @berker_atel 

Do you have any update on this?

Regards,

[berker_atel · Accepted solution]

Sorry, I' forgot. I reply. A delayed reply better than nothing. 

I wanted to send a test image to VGA screen directly without writing any logic. For this i used to need matching blanking intervals. 

Now i do it with controlling tready of VGA logic. I'm doing tready low during blanking intervals. I think this way is better.