STM32MP151. Display controller questions.

[BReib.1]

1. Can the display interface be driven by the M4 core while the A7 core is powered down?

1a. Can the AXI interconnect peripherals be driven by the M4 while the A7 cores are powered down?

2. Display controller - is there any loss in performance if using an external display controller via SPI interface instead of using the native RGB LTDC interface directly to a display?

[Erwan SZYMANSKI]

Hello @BReib.1​ ,

1) just to be clear, M4 core cannot work with A7 completly shutdown. At least, it needs to be in a very low power mode, but keep in mind that you need A7 to have the M4 working.

2) Concerning display, in theory you can do it with SPI, I2C, FMC... a lot of IPs can driver display, if you have everything working behind. Of course, it will probably impact performances. You need to use tinyDRM for this kind of interfaces, but you have to know that it will so not use neither LTDC nor GPU.

Performances will so depend on the interface speed.

Kind regards,

Erwan.