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FDumontKeller
Associate II
March 20, 2024
Solved

How to wake up CPU1 with RF subsystem?

  • March 20, 2024
  • 2 replies
  • 2083 views

Hi everybody, 

how can the CPU1 of module STM32WB5MMG be waken up by the RF subsystem?
The idea in mind is to use the module as a BLE Server, have the CPU2 perform advertising while the CPU1 is in STOP2 mode. 
According to the reference manual RM0434, this could be done? 

FDumontKeller_1-1710947379513.png

 

FDumontKeller_0-1710946673367.png

And in the Datasheet of STM32WB55xx, the RF is listed as a possible wake up source as well.

FDumontKeller_2-1710947603821.png

Waking up with the the RTC, an EXTI event and EXTI interrupt worked, but the CPU2 stops its advertising shortly after the CPU1 goes to STOP2 mode, even though the low power mode for the CPU2 is disabled. 

FDumontKeller_4-1710948063131.png

I thought that the CPU2 would continue the adversiting and either the EXTI listed as "CPU2 SEV interrupt..." or "PWR switching on the fly, ..." could wake up the CPU1 if a connection is requested from the client. 

FDumontKeller_5-1710948261699.png

Obviosly I am missing somehting, does anybody has an idea of what am I getting wrong?

Thanks in advance!

 

 

This topic has been closed for replies.
Best answer by STTwo-32

Hello @FDumontKeller 

Yes, it is possible for the M4 core to enter the stop2 mode while keeping the M0+ core advertising. The LPM manager is managing it. Note that there is no need to wake up the M4 core when a scan request is received by the MO+. The data to be inserted in the scan response is managed by the M0+ core alone.

Best regards.

STTwo-32

2 replies

STTwo-32
STTwo-32Best answer
ST Technical Moderator
May 20, 2024

Hello @FDumontKeller 

Yes, it is possible for the M4 core to enter the stop2 mode while keeping the M0+ core advertising. The LPM manager is managing it. Note that there is no need to wake up the M4 core when a scan request is received by the MO+. The data to be inserted in the scan response is managed by the M0+ core alone.

Best regards.

STTwo-32

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FDumontKeller
Associate II
May 21, 2024

Hi @STTwo-32
After reading in more detail how the LPM works and manages the transisions of between low power modes while using a BLE application, it is more clear to me how to use it. 

thanks for the answer!!
Best Regards.