STM32F750Z8 Custom Board-TFTLCD shows partial screen

[Muharrem]

Hello everyone.

I have my custom board.

STM32F750Z8 CPU with MT25QL128ABA External Flash.

I don't have external RAM. 

My application code runs at External Flash. It is a simple code. I create just one screen at the TouchGFX and add two buttons. No other screens, no interactions... It's very light code.

I try to communicate 4.3(480x272) TFT-LCD. But it doesn't show full screen. Bottom of the screen is missing. (Image attached).

I tried different "buffer addresses" like 0x20000000(DTCM) and 0x20010000(SRAM1). SRAM1 address is more reliable. I tried to change "Signal Polarity" but it didn't affect.

Thanks for helping.

CubeIDE version 1.6.1

TouchGFX version 4.16.0

Windows 7

[Muharrem]

LTDC settings and TFT-LCD timing attached.

   

[MM..1 · Accepted solution]

Simple 320 Kbytes of SRAM (including 64 Kbytes of Data TCM RAM for critical real-time data)

480x272x3 oversized your ram. Use RGB565 or L8

[Muharrem]

Hi. Thanks for the response.

I got no error about "RAM Size". But i have tried RGB565 just incase. Nothing changed.

By the way, i know internal RAM is not enough for simple 480x272 image. That's why i used "box" instead of "image".

Surprisingly;

When i set RGB888, RAM Usage:49,35KB

When i set RGB565, RAM Usage:49,29KB

[MM..1]

RAM is not counted when you choice config by address in touchGFX and RGB565 is not simple change . Primary you must change it in Layer 1 LTDC config not diplay config

[Muharrem]

@MM..1 Thanks for the replies. I was wrong about the Buffer size.  Now it works with RGB565. I think I forgot to recompile TouchGFX project after I changed the RGB565 settings. That's why i got same error after RGB565 settings.