STM32 LTDC - Maximum resolution

[Thomas L.]

I am planning to interface a STM32H753XI to a 1400x480 display. Here is the reference manual. Now, the maximum resolution given for the STM is 1024x728. I understand that this is the maximum frequency the device can actually output.

Now my desired horizontal resolution exceeds the controllers 1024 pixels. I checked with the registers and they support 11 bit values (so everything up to 2047). Has anyone tried to interface a display with a larger horizontal resolution to an STM? Are the horizontal and vertical pixels a hard limit or is the combined pixel clock frequency the actual limit?

[oleksandr.karbivsky · Accepted solution]

Hi. Read this Application Note. You can achive 1400x480 LTDC resolution with some limits (32-bit SDRAM bus width, 16bpp or 8bpp color depth).

[Thomas L.]

Thank you, that is a great document.

[Tesla DeLorean]

+1 on the 32-bit memory, with high resolutions the bus bandwidth, and interaction between other subsystems becomes highly prescient.

Consider a) your ability to paint and update the frame buffer, b) read data from other time constrained sourced, ie eMMC or SDCard

Some of the DISCO designs use 16-bit wide memory to free up pins, but this also limits performance.

[Thomas L.]

Thank you for your insight on this, @Community member​ , highly appreciated.

[CodeWander]

Hi clive 1. Sorry for the intrusion. I asked this in a separate thread (with now reply, so far :downcast_face_with_sweat: ), How to enable a third party 3.5" NewHaven Display (320x240!!) connected to the LTDC port on STM32MP157C-EV1 board? Do I need to modify some config file to load the LTDC driver, or the device tree files (and rebuild linux...)? I want to display the default apps that come with the STM32MP157C-EV1 on this second 3.5. How do I enable the LTCD display driver? Do I physically remove the original 5.5" display form the DSI port?