STM32H745 Dual Core Power Management

[YSN]

I am running FREERTOS on both M7 and M4 on STM32H745 MCU. In general M7 gets booted up and release HSEM for M4 then it will start.

Now my question , if there no activity in M7 (idle mode), would like to keep M4 actively running and put M7 in sleep. Is it possible to keep M7 in sleep and still continue to run M4 to save power ?. If so how to enable this scenario and what is the way to wake up back the M7 ? Should it be again through M4 or it can done from any peripheral interrupt like touch or keys etc ?

Although H7 series is performance device, we are using it in battery based application. Could you suggest best power management options

for D1, D2 and D3 domains under FREERTOS. are there any APIs already for achieving above scenario?

[Bouraoui Chemli]

Hi,

You can refer to application note AN5215 "STM32H747/757 advanced power management", mode 2 is similar to your use case.

Also, you can refer to FreeRTOS example available in STM32CubeH7 firmware via this path: STM32Cube_FW_H7_V1.9.0\Projects\STM32H745I-DISCO\Applications\FreeRTOS

Bouraoui

[YSN]

What is minimum frequency at which we can still see touchgfx GUI. I mean the GUI is not getting up with VOLTAGE SCALE3.. Only SCALE1 and SCALE2 are working.. Is there any minimum required frequency for LTDC and touchgfx?