How to check if it is a VBlank period

[zakio]

I am using MIPI-DSI on i.MX 7Dual.
I'm trying to switch from HS mode to LP mode while drawing and read the registers on the LCD panel. I would like to do this during the Vblank period. Is there a way to check if it is during the Vblank period?

[igorpadykov]

Hi zakio

>. Is there a way to check if it is during the Vblank period?

sorry this is not possible as LPDT (enter to LP mode) area is not within VSYNC as described in
Figure 13-36. Stable VFP Area Before Command Transfer Allowing Area

i.MX 7Dual Applications Processor Reference Manual

Best regards
igor

[zakio]

Hi igor

Thank you for your reply.
Does that mean I can't switch from HS mode to LP mode while drawing (from VSync to the next VSync)?
During the VBlank period, I'm thinking of stopping drawing and then switching.

Best regards

zakio

[igorpadykov]

Hi Zakio

please refer to Figure 13-36. Stable VFP Area Before Command Transfer Allowing Area-

it shows area where it is possble:

"Only this area ..command through LPDT or HS (register configuration)"

i.MX 7Dual Applications Processor Reference Manual

Best regards
igor