STM32L4xx Low power modes

bareil76 · ‎2024-02-14

Hi all,

I am designing an application on a STM32L431. I need to consume the least amount of power. The MCU will have to use the CAN module both in transmit and receive mode.

The reference manual does not give too much details on how the lower power mode work with each of the peripherals.

For example, if I set the device in low-power sleep mode and I receive a CAN message, it will wake up the CPU clock and main loop restart?

Can I set the Tx mailboxes of the CAN buffer and immediately send the device in low-power sleep mode? The CAN message will be sent anyway?

waclawek.jan · ‎2024-02-14

Generally, the mcu wakes up from most (but the lowest-power) modes through interrupts.

If given peripheral is "functional" in the above table, then its clock thus its internal machine keeps running during the low power mode.

Read 5.3 Low-power modes chapter in RM0394, it outlines all the requirements (among other things, also the constraints "low-power run" and "low power sleep" put on system clock frequency).

JW

View solution in original post

waclawek.jan · ‎2024-02-14

Generally, the mcu wakes up from most (but the lowest-power) modes through interrupts.

If given peripheral is "functional" in the above table, then its clock thus its internal machine keeps running during the low power mode.

Read 5.3 Low-power modes chapter in RM0394, it outlines all the requirements (among other things, also the constraints "low-power run" and "low power sleep" put on system clock frequency).

JW