ST STM32L0x3 - Page 975

RM0367 Rev 7 975/1043
RM0367 Code examples
1020
tickstart = Tick;
while ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL) /* (4) */
{
if ((Tick - tickstart ) > CLOCKSWITCH_TIMEOUT_VALUE)
{
error = ERROR_CLKSWITCH_TIMEOUT; /* Report an error */
return;
}
}
Note: Tick is a global variable incremented in the SysTick ISR each millisecond.
A.3 NVM Operation code example
A.3.1 Unlocking the data EEPROM and FLASH_PECR register
code example
/* (1) Wait till no operation is on going */
/* (2) Check if the PELOCK is unlocked */
/* (3) Perform unlock sequence */
while ((FLASH->SR & FLASH_SR_BSY) != 0) /* (1) */
{
/* For robust implementation, add here time-out management */
}
if ((FLASH->PECR & FLASH_PECR_PELOCK) != 0) /* (2) */
{
FLASH->PEKEYR = FLASH_PEKEY1; /* (3) */
FLASH->PEKEYR = FLASH_PEKEY2;
}
A.3.2 Locking data EEPROM and FLASH_PECR register code example
/* (1) Wait till no operation is on going */
/* (2) Locks the NVM by setting PELOCK in PECR */
while ((FLASH->SR & FLASH_SR_BSY) != 0) /* (1) */
{
/* For robust implementation, add here time-out management */
}
FLASH->PECR |= FLASH_PECR_PELOCK; /* (2) */
A.3.3 Unlocking the NVM program memory code example
/* (1) Wait till no operation is on going */
/* (2) Check that the PELOCK is unlocked */
/* (3) Check if the PRGLOCK is unlocked */
/* (4) Perform unlock sequence */
while ((FLASH->SR & FLASH_SR_BSY) != 0) /* (1) */