Do you recommend TocuhGFX @ 1024x600 pixels

[ali_dehbidi]

Hi,

I want to use STM32H750XBH6 part with a LCD of 24bit @1024x600 resolution, Do you have any Idea about the performance? is it slow or can it do the job?

[ktrofimo]

I do have now H743 @480MHz with 32bit SDRAM @133MHz​. With RGB565 I have a feeling it is just at the edge of performance. Sometimes I see glitches and I can eliminate them only by simplifying screen layout. SDRAM is fast enough (I was successful even in 16bit bus mode)

[Tesla DeLorean]

1024x600 @ 60 Hz 24-bpp gets pretty close to the DSIHOST bandwidth ceiling.

Are you sure you need 24-bit? Lot of pins, and +50% of the bandwidth of 16-bit

Pixel clock around 40 MHz as I recall, at 60+ MHz you're probably close to the top end of the resolutions drivable by the STM32 MCU, would really want 32-bit wide SDRAM path, especially for concurrent operation with SDMMC or DCMI

H750, probably most code in QSPI, cache will mask a lot of that, but still an underlying bottleneck, and not sure how it impacts latency and contention.

Hopefully one of the TouchGFX crew has some handy performance slides..

[ali_dehbidi]

ktrofimo did you use 1024x600 pixels @ 16Bit? Also did you use some widgets like analog clock, graph and Date Picker?

What about putting the application code into the SDRAM too, so the QSPI is not a bottleneck. Also using the 32bit SDRAM.

[ktrofimo]

I would NOT recommend to use SDRAM for any other purpose besides video buffer. Concurrent access to the SDRAM bus during frame draw by LTDC will produce ​flickering and artifacts.

Widgets - yes, analog clock, dynamic graph in scroll mode with filled semi-transparent area under the line, dozen text fields updated several times per second...​