2026-02-22 9:35 PM - last edited on 2026-02-22 10:53 PM by Imen.D
Hello,
I have a project on STM32WL55 which runs on dual core CM0+ and CM4.
When i put it in debug mode using the development board STM32WL55 Nuleo-64 (NUCLEO-WL55JC1), it goes into debug mode without any issue. Both the cores are getting debugged.
Procedure :
Launching the configurations
Launch the Cortex®‑M4 configuration to download both the Cortex®‑M0+ and Cortex®‑M4 images.
Resume the Cortex®‑M4 core until the C2BOOT bit is set in power control register 4 (PWR_CR4) to enable
the Cortex®‑M0+.
Launch the Cortex®‑M0+ configuration using the arrow next to the debug icon. The Cortex®‑M0+ is in the
running mode and the user can halt it after the debugger is started.
Now, I want to debug the same code in a customized PC having STM32WL55CCU6. It is not going in debug mode which means it gets stuck here :
void MBMUXIF_SystemSendCmd(FEAT_INFO_IdTypeDef SystemPrioFeat)
{
/* USER CODE BEGIN MBMUXIF_SystemSendCmd_1 */
/* USER CODE END MBMUXIF_SystemSendCmd_1 */
if (SystemPrioFeat == FEAT_INFO_SYSTEM_ID)
{
MbSystemRespRcvFlag = 0; /* To avoid using Sequencer during Init sequence for SysCmd */
if (MBMUX_CommandSnd(FEAT_INFO_SYSTEM_ID) == 0)
{
if (AllowSequencerForSysCmd)
{
UTIL_SEQ_WaitEvt(1 << CFG_SEQ_Evt_MbSystemRespRcv);
}
else
{
/* To avoid using Sequencer (& LowPower) during Init sequence for SysCmd */
while (!MbSystemRespRcvFlag) {}
}
}
else
{
Error_Handler();
}
}
else
{
/* USER CODE BEGIN MBMUXIF_SystemSendCmd_2 */
/* USER CODE END MBMUXIF_SystemSendCmd_2 */
}
/* USER CODE BEGIN MBMUXIF_SystemSendCmd_Last */
/* USER CODE END MBMUXIF_SystemSendCmd_Last */
}
In the above code MbSystemRespRcvFlag never becomes 1 from 0 due to which it gets stuck in
while (!MbSystemRespRcvFlag) {} loop forever.
But the above issue does not occur with NUCLEO-WL55JC1 development board.
It displays the msg :
STM32WL55 DUAL CORE DEBUG ERROR MSG : Failed to execute MI Command: - exec-next 1 Error message from debugger backend: Cannot find bounds of current function.
I have tried all possible solutions but unable to figure out the issue.
Please help me to find where is the issue.
Thanks.
2026-02-22 10:51 PM
Hello @Somya
I recommend the following application notes: AN5564 and AN5556. These documents describe how to get started with projects based on STM32WL Series dual-core microcontrollers and highlight important considerations when debugging a device in the STM32WL Series.
2026-02-23 1:47 AM
Hello,
Thanks for replying.
I have referred to the above document only: AN5564 (Section 3.1.1)
The way the document states , I have done the same way only and it is running on development board STM32WL55 Nuleo-64 (NUCLEO-WL55JC1) correctly.
But the customized board used is having STM32WL55CCU6 in which it is unable to go into debug mode.
Is it due to the difference in STM32 on development board(STM32WL55JC1) and customized board(STM32WL55CCU6) ?
Is there any modifications that needs to be done in the code while running on customized board(STM32WL55CCU6) as i have enabled from 0 to 1:
1. In CM0+
**
* @brief Disable Low Power mode
* @note 0: LowPowerMode enabled. MCU enters stop2 mode, 1: LowPowerMode disabled. MCU enters sleep mode only
*/
#define LOW_POWER_DISABLE 1
2.In CM4
/**
* @brief Enable/Disable MCU Debugger pins (dbg serial wires)
* @note by HW serial wires are ON by default, need to put them OFF to save power
*/
#define DEBUGGER_ENABLED 1
/**
* @brief Disable Low Power mode
* @note 0: LowPowerMode enabled. MCU enters stop2 mode, 1: LowPowerMode disabled. MCU enters sleep mode only
*/
#define LOW_POWER_DISABLE 1
Is there any further changes that needs to be done in the software? Or is it due to the hardware difference in STM32 on development board(STM32WL55JC1) and customized board(STM32WL55CCU6) ?
Thanks