HAL_RCC_EnableCSS() function
Enables the Clock Security System.
Syntax
void HAL_RCC_EnableCSS(void);
Return value
None
Notes
If a failure is detected on the HSE oscillator clock, this oscillator is automatically disabled and an interrupt is generated to inform the software about the failure (Clock Security System Interrupt, CSSI), allowing the MCU to perform rescue operations. The CSSI is linked to the Cortex-M4 NMI (Non-Maskable Interrupt) exception vector.