Hi,
I am trying to write a battery powered application with a STM32WL5MOC. The LoRa capability and the form factor are crucial. The dual-core feature unfortunately makes everything so much more complex. I only need the CM0+... so in the future the CM4 shall stay in stop/standby mode, but for simplicity it's currently running in a while(1) loop.
Now I simply want to set CM0+ into stop mode to save some power, so I did this:
volatile uint8_t lptim_timeout_flag = 0;
void HAL_LPTIM_CompareMatchCallback(LPTIM_HandleTypeDef *hlptim)
{
if(hlptim->Instance == LPTIM1)
lptim_timeout_flag = 1;
}
void HAL_Delay(uint32_t ms)
{
/* Suspend SysTick to prevent periodic wake-ups. */
HAL_SuspendTick();
/* Reset the LPTIM timeout flag. */
lptim_timeout_flag = 0;
/* Start LPTIM in timeout mode. */
if(HAL_LPTIM_OnePulse_Start_IT(&hlptim1, ms, ms) != HAL_OK)
Error_Handler();
/* Enter STOP mode */
while (ms > 0 && lptim_timeout_flag == 0)
// {} WORKS
// __WFI(); WORKS
// HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI); NEVER returns???
/* Execution resumes here after wake-up */
/* Clear Stop2 flag of CPU2 */
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_C2STOP2);
//QUESTION: can CPU2 do this?
SystemClock_Config();
//ALTERNATIVE approach wake up CPU1 to reconfig clock (in case it sleeps as well)
HAL_HSEM_Take(HSEM_ENTERSTOP, HSEM_PROCESSID_MIN);
while(HAL_HSEM_IsSemTaken(HSEM_ENTERSTOP) == 0);
HAL_HSEM_Release(HSEM_ENTERSTOP, HSEM_PROCESSID_MIN);
HAL_LPTIM_OnePulse_Stop_IT(&hlptim1);
/* update time */
uwTick += ms;
HAL_ResumeTick();
}
{} and __WFI() both work, but are not as efficient as the real deal: HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);
However, it seems to never return, also the interrupt is working?! I must admit i loose the debugger during this call as well. HAL_EnableDBGStopMode(); seems not to be available for the CM0+?
[I have a follow up questions: once this is solved: Can CM0+ config the system clock as well, or do i need to wake up CPU1 for this job? Already tried the latter, that seems to work.]
Now, back to my main problem. I tried to wake the CPU2 in line 24 by using an external interrupt (EXTI). But I must admit I even failed to configure it... Sure I configured a pin as GPIO_EXTIx but in NVIC2 all the EXTI lines are grayed out, for BOTH CPUs (=NVIC1 as well). I have seen other assiging the interrupt pin to a certain CPU like so:
But this option is not available for my GPIOs? The picture shows its for an I2C pin, which i can't select anything. No matter what i press, it always shows 'free'???
So I tried to configure everything manually:
/* USER CODE BEGIN 1 */
#if 0
/* USER CODE END 1 */
/** Pinout Configuration
*/
void MX_GPIO_Init(void)
{
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
}
/* USER CODE BEGIN 2 */
#endif
//note: due to some reason it does not generate GPIO code... so we have to do it...
void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/* Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
/* Configure GPIO pins : LED_Pin */
GPIO_InitStruct.Pin = LED_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(LED_GPIO_Port, &GPIO_InitStruct);
/* Configure GPIO pin : BTN0_Pin */
GPIO_InitStruct.Pin = BTN0_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(BTN0_GPIO_Port, &GPIO_InitStruct);
HAL_NVIC_SetPriority(EXTI3_2_IRQn, 1, 0);
HAL_NVIC_EnableIRQ(EXTI3_2_IRQn);
}
/* USER CODE END 2 */
Unfortunately with limited success. It wakes up again, i can debug it. BUT if gets stuck in the UART2 Handler which is not configured at all (=some random place indicating that something is wrong).
So why doesn't the configurator allow me to asign various GPIOs to individual CPUs (incl EXIT) and why isn't the code generated? I am missing something here?!
Thanks in advance!
Juergen
