SAM3S_14 Datasheet, PDF (62/1087 Pages) ATMEL Corporation – AT91SAM ARM-based Flash MCU

Table 11-9. Properties of the different exception types (Continued)
Exception
number ⁽¹⁾
IRQ
number ⁽
1)
Exception
type
Priority
Vector address
or offset ⁽²⁾
5
-11
Bus fault
Configurable
(3)
0x00000014
6
-10
Usage fault
Configurable
(3)
0x00000018
Activation
Synchronous when
precise,
asynchronous when
imprecise
Synchronous
7-10
-
11
-5
-
SVCall
-
Configurable
(3)
Reserved
0x0000002C
-
Synchronous
12-13
-
14
-2
-
PendSV
-
Configurable
(3)
Reserved
0x00000038
-
Asynchronous
15
-1
SysTick
Configurable
(3)
0x0000003C
Asynchronous
16 and
above
0 and
above ⁽⁴⁾
Interrupt (IRQ)
Configurable 0x00000040 and
(5)
above ⁽⁶⁾
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 46.
2.
See “Vector table” on page 63 for more information.
3.
See “System Handler Priority Registers” on page 171.
4.
See the “Peripheral Identifiers” section of the datasheet.
5.
See “Interrupt Priority Registers” on page 153.
6.
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 11-9 on page 61 shows as having configurable priority,
see:
• “System Handler Control and State Register” on page 174
• “Interrupt Clear-enable Registers” on page 149.
For more information about hard faults, memory management faults, bus faults, and usage faults, see “Fault han-
dling” on page 66.
11.5.3 Exception handlers
The processor handles exceptions using:
11.5.3.1 Interrupt Service Routines (ISRs)
Interrupts IRQ0 to IRQ34 are the exceptions handled by ISRs.
11.5.3.2 Fault handlers
Hard fault, memory management fault, usage fault, bus fault are fault exceptions handled by the fault handlers.
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