Does STM32H7R7 LTDC support DE mode only?

[Leo2Ruan]

Hi,

I am evaluating the STM32H7R7Z8J6, intended to working with a TFT-LCD which is working in parallel RGB interface with DE mode only. The HSYNC and VSYNC signals are not connected.

Both AN4861 (Introduction to LCD-TFT display controller (LTDC) on STM32 MCUs) and RM0477 (STM32H7Rx/7Sx Arm®-based 32-bit MCUs) documents only SYNC+DE mode, but the does not mention if the DE-mode-only is supported or not? Could you help to point out the documentation where explains how the LTDC working for DE mode in detail? 

Thanks!

Leo

[MKANO.2 · Accepted solution]

Hello @Leo2Ruan 

In general, the 3 signals DE, HSYNC and VSYNC are always produced by LTDC.
The enable is done at GPIO level selecting if the corresponding alternate function is selected or not.
DE mode can mean DE+HSYNC+VSYNC whereas HS or HSYNC/VSYNC mode means HSYNC+VSYNC only
So, If you want DE mode with just DE signal, you don't have to program anything in LTDC, just do not enable HSYNC and VSYNC

Best regards,

Mariem