STM32F7/H7 and ultra-wide display

[Artur Laskowski]

Posted on April 03, 2018 at 11:34

Is there any possibility that STM32F7/H7 chip can drive an LCD-TFT 1600x480 display, or the XGA resolution is unbreakable limit for the controllers? Maybe someone tried something similar before and can share with his/hers experience?

[Imen.D]

Posted on April 03, 2018 at 13:56

 Hello amlas,

In the main, when talking about a particular resolution, we have to consider some important parameters such as:color depth, pixel clock and SDRAM bus width (if it’s used for the frame buffer), as well as a configuration RGBXXX and LTDC layer number.

So, we can’t talk about resolution asyou should precise the Display’s pixel clock PIXCLK and the color depth (bpp) as well. Then, based on this pixel clock and the color depth bpp, you should follow the section “4.2 Checking the display size and color depth compatibility with the hardware configuration�? in the https://www.st.com/content/ccc/resource/technical/document/application_note/group0/25/ca/f9/b4/ae/fc/4e/1e/DM00287603/files/DM00287603.pdf/jcr:content/translations/en.DM00287603.pdf application note.

You have to check if the PIXCLK display is supported by the MCU. Then, the display's PIXCLK must not exceed the PIXCLK max of the MCU specified in the AN4861(see table 11) . 

Please note that the AN4861 is a very detailed LTDC application note explaining many important aspects such as display resolution compatibility and performances aspects with detailed examples.

Hoping this helped you.

Best Regards,

Imen

PS: Edited on 27/09/2019 by Amel NASRI to fix link to AN4861

[Artur Laskowski]

Posted on April 03, 2018 at 20:38

Dear

DAHMEN.IMEN

,

Thank you for your response. This application note is very useful. As I see, it's possible to drive my display under some specific circumstances: 16 bpp color depth, 32-bit SDRAM, one LTDC layer and 50 to 60 MHz pixel clock.

I had to miss this note when I was looking for information on this subject, probably because I was initially looking at H7 family resources. According to this note, that configuration should worked for both STM32F4 and F7 familiy.

I suppose that for STM32H7 family this application note works the same as for F4/F7 families. Unfortunately, there is lack information about this, moreover, STM32CubeMX has locked max values of Active Width/Height for H7 family, which is very confusing.

Best regards,

Artur

[Imen.D]

Posted on April 04, 2018 at 10:55

Hi

Laskowski.Artur

,

This

AN4861

application note is applicable also for STM32H7 and will be updated in the coming releases to add the STM32H7related information.

Best Regards,

Imen