Why Some time it's Shows in display?

[GMano.1]

Hai.

I have to use STM32F746IGT Custom board and 7inch display 800x480,

SDRAM 16MB External flash 128MB Micron.

I am using Starting Address of SDRAM 0xD0000000, Just create one screen and two Toggle switchs.

Run the code display show some colors or half display only

If i change Starting address from 0xD00 to 0xC00 it's show white screen,

Change to 0xD00 display show and working fine (Some time in first attempt).

Once switch OFF and ON the controller again have a same problem.

Starting Address it works irregularly.

Where i am doing mistakes.

Thanks & Regards

M.Govind

[Alexandre RENOUX]

Hello GMano.1,

I'm sorry but unfortunately I don't understand what you're saying.

When setting the starting address to 0xD00 (meaning external RAM) : Does it work all the time ? If not, when does it not work ?

When setting the starting address to 0xC00 (meaning internal RAM) : Does it work all the time ? If not, when does it not work ? Are you sure you have enough space for your framebuffers ? What display interface do you use ? LTDC ?

/Alexandre

[GMano.1]

Hello Alexandre RENOUX,

Yes..., I am using LTDC Interface.

I am using display pixel 800X400, SDRAM 16MB (Part No of SDRAM : ISSIIC42S16400J-7TL).

So my Start Frame Address 0xD0000000 and my Second Frame Address is 0xD00BB800.

16 Mbytes SDRAM.

800*480* (16 / 8) = 768000 bytes = 0xBB800.

768000 / 1024 = 750 Kbytes.

2 Framebuffers 750 * 2 = 1500 Kbytes.

Is this is enough for it or not?

Please let me know.

By

M.Govind. 

[Alexandre RENOUX]

Hello GMano.1,

Right now I don't really know how to help you.

Can you confirm if what is written below is correct ?

"

When selecting the starting address of the SDRAM to 0xD0000000, the UI is not displaying correctly.

But if you then select 0xC0000000 as the starting address, re-build and download, then change again to 0xD0000000, build and download, it works, is that right ?

"

/Alexandre