 Hello, and welcome to this presentation of the STM32 nested-vector interrupt controller. We will be presenting the features of this controller. The nested-vector interrupt controller embedded inside of the STM32-L4 microcontroller provides up to 91 interrupt channels on STM32-L49X4A6 devices served with low latency. One of 16 priorities could be assigned to each interrupt source. The application could benefit from dynamic prioritization of the interrupt levels, fast response to the requests thanks to low latency response and tail chaining, and also from vector table relocation. The NVIC provides a fast response to interrupt requests, allowing an application to quickly serve incoming events. Most of the peripherals have a unique interrupt vector, making development of the application easier with less need to programmatically determine the source of an interrupt during processing. The interrupt vector table can also be relocated, which allows the system designer to adapt the placement of interrupt service routines to the application's memory layout. The NVIC provides several features for efficient handling of exceptions. When an interrupt handler is served and a new request with higher priority arrives, the new exception can preempt the current one. This is called nested exception handling. The previous exception handler resumes execution after the higher priority exception is handled. When there is an interrupt request with low priority raised during execution of an interrupt handler, it becomes pending. Once the current interrupt handler is finished, the context saving and restoring process is skipped and control is transferred directly to the new exception handler to decrease interrupt latency. When an interrupt arrives, the processor first saves the program context before executing the interrupt handler. If the processor is performing this context saving operation when an interrupt of higher priority arrives, the processor switches directly to handling the higher priority interrupt when it is finished saving program context. When all of the exception handlers have been run and no other exception is pending, the processor restores the previous context from the stack and returns to normal application execution. When accessing the NVIC registers, ensure that your code uses correctly aligned register access. Unaligned access is not supported for NVIC registers. An interrupt becomes pending when the source asks for service. Handling of the interrupt only prevents the processor from taking that interrupt. Make sure the related interrupt flag is cleared before enabling the interrupt vector. Before relocating the vector table using the VTOR register, ensure fault handlers, NMI and all enabled interrupts are correctly set up on the new location. For detailed information, please refer mainly to Programming Manual PM0214.