Is it possible to have TouchGFX support XGA (1024 x 768) LCD

Zli.1 · ‎2020-01-30

Hi all,

I am working on a project that requires a GUI with high resolution. I created a very simple TouchGFX project on a Sharp XGA LCD with a STM32H743 evaluation board. I got glitches between screen transitions. According to ThouchGFX specification, the maximum resolution it supports is 1024 x 720. My questions are, is the glitch caused by the limitation of the resolution? Is it possible to make TouchGFX support higher resolution? Thank you very much.

Zhao Li

JChan.7 · ‎2020-02-04

Hello Zli.1

You can check the SDRAM setting , GPIO output speed and HCLK.

Zli.1 · ‎2020-02-04

Hi JChan,

Thank you for your reply. My SDRAM is working fine. I have already enabled the MPU, so the read and write speed is fast enough to support XGA. I also have tried different LCD pin configuration, making them working under different speed mode. It does not help. As for the HCLK, I slowed don the clock for LTDC to 40MHz, TouchGFX can work with very few tear effect. But because of the clock is a lot lower than the suggested frequency (60Mhz) of the LCD, I can see a few flicker. I have already contact the ST technical support, hope they can give me some suggestions. Thanks.

Zli.1 · ‎2020-02-11

Hi JChan,

Thanks for your answer. Yes, you are right. In my SDRAM settings, I forgot to turn on the burst read. After doing this, the tear effect issue improves. Now my LCD can go with a 66 MHz clock. But along with the increment of the frame rate, I'v got some side effects. Touchgfx is using LTDC clock for the tick event. It seems that the tick event on my board is a lot faster than it was on the simulator. On the simulator, the frequency of tick event is 60 Hz. Plus, the screen transition loses the transition animation.

I am in touch with the ST technical support, hope they can give out some solution. Thanks.