Using the STM32 LTDC display controller, can the framebuffer be the same size as a layer?

[michaelm000]

Posted on February 06, 2018 at 00:42

Using the STM32F756. 

I have a full screen graphic on one layer and some text on another layer. I just need to update the text and not the whole screen. So, if I define the text layer size just big enough to cover the text, will that reduce the effective framebuffer size? That is, can I reduce the required frambuffer memory requirements by using a smaller layer or does the LTDC still require a full screen amount of contiguous memory to operate and just ignore values outside the layer?

Thanks!

#lcd #display #ltdc #tft

[markus239955_stm1_stmicro_com]

Posted on February 06, 2018 at 16:46

Hello Mathias,

the Timings / Resolution of the sync signals Need to match your Display, your layer Resolution only Need to match your Needs. with smaller Resolution of a layer than the Screen, you save Memory size and Memory bandwidth. As far as i remember, some examples in the CubeMX repositories Showcase this, too. See the STM32F746G-disco LTDC examples with 2 layer using the 480x272 TFT screen with two different 320x240 Layers.

Best regards,

Markus.