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Cannot connect SWD J-link GDB Server to STM32 MCU in stop mode

Question asked by jdx on Jan 31, 2014
Latest reply on Feb 1, 2014 by jdx
Hi all,

I wrote a small program for testing a STM32L152CBT6 Stop Mode via command PWR_EnterSTOPMode(PWR_Regulator_LowPower, PWR_STOPEntry_WFI).
The program switches to stop mode immediatelly after MCU starts and after 4 seconds the RTC clock IRQ wake up the MCU.
This sequence runs in while(1) cycle and writes via SWO ITM_SendChar sentences "going to stop..." and "wake up".
Everything works perfectly well BUT after I've disconnected SWD J-Link GDB Server it is not possible to connect again :-(.


The Segger J-link GDB server just writes:
3,3V 
...
Connecting to target...ERROR...Could not connect to target
Target connection failed. GDB Server will be closed.
...and GDB server finishes running.


I've tried various reset types in J-Link, J-LinkSTM32 for reset the MCU to default state but with no success.

I think the Debug engine is not running in stop mode and the J-Link GDB server cannot detect the target.

Please help me how can I reset the MCU a flash or erase the program in memory.


Thanks
jdx

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