Not entering to sleep mode immediatly after Programming STM32 controller using STlink programmer

darshan-ltts · ‎2024-05-22

I am working with STM32 U575/U5A5 and L4 series of STM32 controllers in low power mode. I have programmed the controller to wake for every 10s and blink LED. This issue what we observed is once immediately flashing hex file to controller using STlink programmer, Controller is not entering in sleep mode LED will be keep on blinking. If I remove the power and connect it back, Controller is entering sleep mode and waking up for every 10s as expected.

we have reseted the controller using Reset button, but still controller is not entering to sleep mode.

The question here is why Controller requires power on reset to enter power saving mode after flashing hex file to controller using STlink programmer?

Andrew Neil · ‎2024-06-28

So the MCU does still behave the same as if went to sleep - you just don't get the power reduction.

So this doesn't explain why @darshan-ltts does see different behaviour.

darshan-ltts · ‎2024-06-28

@Andrew Neil No... It won't go to sleep. Means If I configure wakeup for 10s, It'll wake up immediately and power consumption is also more. Problem is as per our product requirement, if main power is not available, Controller we are keeping in sleep mode and we are expecting the backup of 50Hrs and device is Potted., If we flash the firmware from the cube programmer, we need to keep for 3-4hrs to discharge and then need to test the functionality.

MM..1 · ‎2024-06-28

Try place in your code reset DBG CR to zero. Or you in programmer activate RDP option bytes, this is next block require power off... And you still write about sleep mode , but real preserve is STOP mode.

BarryWhit · ‎2024-06-28

@darshan-ltts , the real problem here is that none of us can be sure we understand what problem you're describing due to language barrier. Please make an effort to be as clear as possible.

My initial post suggested a very quick and concrete test for you to make, which would clarify things. Have you done the test I described? what are the results?

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Andrew Neil · ‎2024-06-28

@darshan-ltts wrote:
It won't go to sleep. Means If I configure wakeup for 10s, It'll wake up immediately

That doesn't really make sense - if it never goes to sleep, how can it ever wake up?

Again, have you tried this in the debugger to see what's happening?

@darshan-ltts wrote:
and power consumption is also more.

That is to expected - @MM..1 explained the reason.

darshan-ltts · ‎2024-06-28

If I do power cycle not button reset. Then I can see device wake up for every 10s

Andrew Neil · ‎2024-06-28

Again, have you tried this in the debugger to see what's happening?

darshan-ltts · ‎2024-06-28

no I haven't tried.. because it is not the usecase for us. Mainly issue is because of production

BarryWhit · ‎2024-06-28

I'm out.

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Andrew Neil · ‎2024-06-28

@darshan-ltts wrote:
no I haven't tried.. because it is not the usecase for us. Mainly issue is because of production

What ??

Do you want to fix this problem?

If you want to fix it, you will need to find it first.

The purpose of using the debugger is to find the problem!