Interrupts and events RM0390
238/1328 RM0390 Rev 4
10 Interrupts and events
10.1 Nested vectored interrupt controller (NVIC)
10.1.1 NVIC features
The nested vector interrupt controller NVIC includes the following features:
• 96 maskable interrupt channels (not including the 16 interrupt lines of Cortex
®
-M4 with
FPU)
• 16 programmable priority levels (4 bits of interrupt priority are used)
• low-latency exception and interrupt handling
• power management control
• implementation of system control registers
The NVIC and the processor core interface are closely coupled, which enables low latency
interrupt processing and efficient processing of late arriving interrupts.
All interrupts including the core exceptions are managed by the NVIC. For more information
on exceptions and NVIC programming, refer to programming manual PM0214.
10.1.2 SysTick calibration value register
The SysTick calibration value is fixed to 18750, which gives a reference time base of 1 ms
with the SysTick clock set to 18.75 MHz (HCLK/8, with HCLK set to 150 MHz).
10.1.3 Interrupt and exception vectors
See Table 38 for the vector table.
10.2 External interrupt/event controller (EXTI)
The external interrupt/event controller consists of up to 23 edge detectors for generating
event/interrupt requests. Each input line can be independently configured to select the type
(interrupt or event) and the corresponding trigger event (rising or falling or both). Each line
can also masked independently. A pending register maintains the status line of the interrupt
requests.
Table 38. Vector table for STM32F446xx
Position
Priority
Type of
priority
Acronym Description Address
- - - - Reserved 0x0000 0000
- -3 fixed Reset Reset 0x0000 0004
- -2 fixed NMI Non maskable interrupt, Clock Security System 0x0000 0008
- -1 fixed HardFault All class of fault 0x0000 000C
- 0 settable MemManage Memory management 0x0000 0010