UM10360 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
User manual Rev. 3 — 20 December 2013 748 of 841
NXP Semiconductors
UM10360
Chapter 34: Appendix: Cortex-M3 user guide
[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 Table 629
.
[2] See Section 34.3.3.4
for more information.
[3] See Section 34.4.3.9 “
System Handler Priority Registers”.
[4] See Section 34.4.2.7 “
Interrupt Priority Registers”.
[5] Increasing in steps of 4.
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.
Privileged software can disable the exceptions that Table 639
shows as having
configurable priority, see:
• Section 34.4.3.10 “System Handler Control and State Register”
• Section 34.4.2.3 “Interrupt Clear-enable Registers”.
For more information about hard faults, memory management faults, bus faults, and
usage faults, see Section 34.3.4
.
34.3.3.3 Exception handlers
The processor handles exceptions using:
• Interrupt Service Routines (ISRs)
Interrupts IRQ0 and up are the exceptions handled by ISRs.
• Fault handlers
Hard fault, memory management fault, usage fault, bus fault are fault exceptions
handled by the fault handlers.
• System handlers
NMI, PendSV, SVCall SysTick, and the fault exceptions are all system exceptions that
are handled by system handlers.
5 -11 Bus fault Configurable
[3]
0x00000014
Synchronous when
precise, asynchronous
when imprecise
6 -10 Usage fault Configurable
[3]
0x00000018
Synchronous
7-10 - - - 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 and above 0 and above Interrupt (IRQ) Configurable
[4]
0x00000040
and above
[5]
Asynchronous
Table 639. Properties of the different exception types
Exception
number
[1]
IRQ
number
[1]
Exception
type
Priority Vector address
or offset
[2]
Activation
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