[SOLVED] [STM32WB] How to put CPU2 in reset state after powering it up?

[Rico]

Hello,

I'm working on a STM32WBRGV6, with dual CPU's, CPU1 for main application and CPU2 for the BLE stack.

I need to make the device ultra low power, and for that I launch the CPU2 in run mode only when I need it (on an external INT), with APPE_Init() function.

I would like to know if there is a way to put it back to a reset state? I can only find commands to release it from reset (with C2BOOT in PWR_CR4 register), but nothing to put it back in reset.

If I put CPU2 in shutdown/standby mode, it is still using too much power for my application.

Thank you in advance,

Rico

[BSpoe.1]

Maybe it's possible to turn off the clock for CPU2 (HCLK2) in RCC configuration?

[Rico]

Hello BSpoe.1,

thank you for your answer.

Since my question I got the answer for my question directly from ST, it is NOT possible to reset it once CPU2 has boot.

The thing is I had several other problems in my firmware, and now they are solved, putting CPU2 in STOP MODE 2 make it consume nearly 0, which is good enough for me.

Best regards,

Rico

[SChan.8]

Hi @Rico​ I am using STM32WB55 microcontroller for my project. I want to put the CPU2 in a Low power mode to save power in my application (with in the code I want to do this as CPU2 is used in some parts of my code). How can I do that ?

[AChil.1]

Hi @SChan.8, Did you manage to put CPU2 into low power mode? I am struggling to do the same and can only get my system down to 3mA when I need somewhere in the uA range. How did you do it?