Black Screen after 4-5 Reboot

[Ngard.1]

Hello,

I'm using STM32H750IB (touchgfx 4.13.0 with freertos  V10.2.1) to control RGB TFT LCD, with external flash and also external SDRAM.

The application runs well but sometimes (after 4-5 reboot) the screen remains black, if I reboot the application starts correctly.

After some tests I found that the LTDC module goes in FIFO UNDERRUN when the black screen happens. SDRAM is initialize in the bootloader and the LTDC is initialize in the application.

How can I solve this problem?

Best Regards

Nicola

[Martin KJELDSEN]

I'm not sure why it would happen after 4-5 reboots. Try reducing the pixel clock a bit to see if you're still having that issue. Or using hal.lockDMAToFrontPorch(true); in your TouchGFXHAL.cpp (initialize()).

This will overall reduce the strain on your memory bus.

 /Martin