I want to switch clock source for decreasing power consumption(WakeUp->MSI->HSE->MSI->STOP2->WakeUp->MSI->...). I use HSE(12MHz) for SYSCLK through PLL(24MHz).
MSI is set 24MHz.
I have three probrems.
- HSERDY doesn't RESET when disabling HSE
- After entering STOP2, the flowing current is abnormally high.
- Never wakeup from STOP2(use RTC WakeUp)
First:
Switching MSI to HSE is always successful. Each time I don't disable MSI.
Switching HSE to MSI and disabling PLL also seems successful. Because this code(HAL_RCC_ClockConfig()) returns HAL_OK.
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
// switching to MSI before disabling HSE
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
_dbgTurnOn_LED();
for (int i = 0; i < 1000000; ++i) {
}
_dbgTurnOff_LED();
for (int i = 0; i < 1000000; ++i) {
}
// Returns HAL_OK
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
{
Error_Handler();
}
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_NONE;
// RCC_OscInitStruct.HSEState = RCC_HSE_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_OFF;
// Returns HAL_OK
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
_dbgTurnOn_LED();
for (int i = 0; i < 1000000; ++i) {
}
_dbgTurnOff_LED();
for (int i = 0; i < 1000000; ++i) {
}
HAL_RCCEx_EnableMSIPLLMode();
Add:I confirmed that HSEON, HSEBYP, PLLON, and PLLRDY was reset after above code excuted(debug using ST-Link and CubeIDE). Only HSERDY bit remained SET.
But when I disable HSE using this code, HAL_RCC_OscConfig() returns HAL_TIMEOUT.
In HAL driver, this func rerutns HAL_TIMEOUT when HSERDY don't reset in 100ms.
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) == HAL_TIMEOUT)
{
// MCU enters here each time
_dbgTurnOn_LED();
for (int i = 0; i < 10000000; ++i) {
}
_dbgTurnOff_LED();
for (int i = 0; i < 10000000; ++i) {
}
/* Initialization Error */
Error_Handler();
}
Add:I confirmed that HSEON, HSEBYP, PLLON, and PLLRDY was reset after above code excuted(debug using ST-Link and CubeIDE). Only HSERDY bit remained SET.
So I think my method disabling HSE is wrong. Following problems should occur with same cause.
- After entering STOP2, the flowing current is abnormally high.
- On this board, when STOP2, usually 100uA, but now 700uA
- Never wakeup from STOP2
If I don't switch to HSE, all procedure(WakeUp->MSI->HSE->MSI->STOP2->WakeUp->MSI->...) successfully works.
