ST STM32F0 Series User Manual

PM0215 The STM32 Cortex-M0 processor
Doc ID 022979 Rev 1 23/91
For an asynchronous exception other than reset, the processor can execute another
instruction between when the exception is triggered and when the processor enters the
exception handler.
Software can disable the exceptions that Table 12 on page 23 shows as having configurable
priority, see:Interrupt clear-enable register (ICER) on page 71.
For more information about hard faults, see Section 2.4: Fault handling on page 28.
2.3.3 Exception handlers
The processor handles exceptions using:
Interrupt (IRQ) A interrupt, or IRQ, is an exception signalled by a peripheral, or
generated by a software request. All interrupts are asynchronous to
instruction execution. In the system, peripherals use interrupts to
communicate with the processor.
Table 12. Properties of the different exception types
Exception
number
(1)
IRQ
number
(1)
Exception
type
Priority
Vector address
or offset
(2)
Activation
1 - Reset -3, the highest 0x00000004 Asynchronous
2 -14 NMI -2 0x00000008 Asynchronous
3 -13 Hard fault -1 0x0000000C Synchronous
4-10 - Reserved - - -
11 -5 SVCall Configurable
(3)
0x0000002C Synchronous
12-13 - Reserved - - -
14 -2 PendSV Configurable
(3)
0x00000038 Asynchronous
15 -1 SysTick Configurable
(3)
0x0000003C Asynchronous
16 - 47 0 - 31 Interrupt (IRQ) Configurable
(3)
0x00000040 and
above
(4)
Asynchronous
1. To simplify the software layer, the CMSIS only uses IRQ numbers and therefore uses negative values for exceptions other
than interrupts. The IPSR returns the Exception number, see Interrupt program status register on page 14.
2. See Vector table on page 24 for more information.
3. See Interrupt priority register (IPR0-IPR7) on page 73.
4. Increasing in steps of 4.
Interrupt Service
Routines (ISRs)
Interrupts IRQ0 to IRQ31 are the exceptions handled by ISRs.
Fault handlers Hard fault is the only fault exception handled by the fault handlers.
System handlers NMI, PendSV, SVCall SysTick, and Hard fault exceptions are all
system exceptions that are handled by system handlers.

ST STM32F0 Series Specifications

General

Brand	ST
Model	STM32F0 Series
Category	Microcontrollers
Language	English