Skip to main content
Alexey Ostrejkovsky
Associate II
December 9, 2020
Solved

How I can distinguish, ALARM A or ALARM B waked up STM32L053 from Standby mode?

  • December 9, 2020
  • 2 replies
  • 1028 views

My controller can be waked up from Standby mode by Alarm A or Alarm B: Alarm A every day and Alarm B every minute. Are there any flags (or another means) to know, what event (Alarm A or B) was cause of the waking? That is the problem, because all registers (excluded PWR_CSR and RTC Backup) "dying" after MCU entering in Standby mode...

This topic has been closed for replies.
Best answer by TDK

> Are there any flags (or another means) to know, what event (Alarm A or B) was cause of the waking?

Read the current RTC value and determine if it's consistent with an every minute or every day wakeup time.

2 replies

TDK
TDKBest answer
December 9, 2020

> Are there any flags (or another means) to know, what event (Alarm A or B) was cause of the waking?

Read the current RTC value and determine if it's consistent with an every minute or every day wakeup time.

"If you feel a post has answered your question, please click ""Accept as Solution""."
Alexey Ostrejkovsky
Associate II
December 11, 2020

Many thanks!

It looks like it will have to be done... STM32L053 has no any alarm flags, which can survive the standby mode.