Hi!
I got an external display RVT50HQTNWC00-B - Riverdi to work with TouchGFX, but only when showing static images/buttons. I am testing STM32H735G-DK and STM32H743I-EVAL in paralell. These boards are using OSPI HyperRAM and SDRAM respectively to store the framebuffer(s).
But for both boards I get the same severe flickering effect :\ when trying to update a simple progressbar every 500ms (see video). The two text areas and button are static objects...
I have read the AN4861 and especially page 37. It seems the LTDC FIFO overrun flag is set in every breakpoint in void LTDC_ER_IRQHandler(void) and I have tried/observed a few things:
- Display is (naturally) set to max frequency 25 MHz
- Same flickering problem with both boards
- Single vs double framebuffer has no effect
- DMA2D has no effect
- Using only one LTDC layer
- Using RGB565 instead of RGB888 gives somewhat less flickering (gives framebuffer line width to 64/128 bytes)
Futher more, I am not sure how these recommendations from AN4861 could be achieved:
-"Update the framebuffer content during the blanking period when the LTDC is not fetching".
-"Use the largest possible memory bus width 32-bit instead of 16- or 8-bit SDRAM/SRAM".
What else can I do..?
Thanks in advance for any hints
