Nested Vectored Interrupt Controller

The NVIC manages all the interrupts and is closely coupled to the processor core.
A list of all available interrupts: interrupt table.

• 91 maskable interrupt channels.
• 16 programmable priority levels.
• low-latency exceptions and interrupt handling.

For external interrupts via GPIO pins go to the EXTI page.

#include "reg_stm32f4xx.h"
 
RCC->APB1ENR |= (0x1 << 0u);          /* Enable TIM2 clock. */
 
/* configure timer */
TIM2->PSC = 84000u - 1u;              /* Counting with f = 84MHz / 84000 = 1MHz */
TIM2->ARR = 512u;                     /* Count to 512 */
TIM2->DIER |= (0x1 << 0u);            /* Enable IRQ */
 
TIM2->CR1 |= (0x1 << 0u);             /* Start timer */

#include "reg_stm32f4xx.h"
 
NVIC->ISER[0] |= (0x1 << 28u);        /* Enable TIM2 global interrupt. */