What is the point of the LCD-TFT controller on the F4/F7 series?

[SLasn.1]

Hi community! :)

I was looking at the STM32 F7 series and F469/479/429/439 which have an LCD-TFT controller. I My knowledge of TFT screens is quite limited, but as I understood it basically is an RGB interface - I was wondering what it adds, since pretty much any STM32 can interface with an LCD-TFT using the F(S)MC interface.

I think I read somewhere that with the controller you can drive a TFT LCD directly, as in without a chip on the LCD? But I could not find any examples of that, the only example I found is the STM32F429-Discovery board but the TFT does have a ILI9341 chip which is controlled using the RGB interface. In this case what is the point - is it not the same as using the FSMC interface?

In my case I was thinking using a small 320x240 TFT LCD, probably Monochrome. Do you guys think I have anything to gain using an STM32 with an LCD-TFT controller?

Thank you very much

Simon

[berendi]

The RGB interface bypasses the framebuffer memory on the panel, the LTDC peripheral transmits the entire contents of the framebuffer memory in the MCU in every refresh cycle. It still requires an LCD controller chip, but it can work with a panel that has no framebuffer memory (GRAM).

The FSMC interface writes data into the framebuffer memory of the panel. It will obviously not work with a TFT panel which has no framebuffer memory of its own. Smaller panels usually have one, larger ones do not.

Both have advantages and disadvantages.

RGB mode allows the MCU to directly address and manipulate the framebuffer contents, move blocks around with DMA2D, blending layers, preparing frames in advance (double and triple buffering) for smooth animation, provided the MCU has enough memory for multiple buffers.

FSMC requires no framebuffer memory allocated on the MCU, e.g. fonts and icons can be stored in flash and directly sent to the panel framebuffer. Useful for microcontrollers with little RAM. Display effects are slow and difficult. Framebuffer memory on TFT panels is not directly addressable.

[SLasn.1]

Great thanks for the info berendi!

Seems like FSMC is the way to go for me then ;)