Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO 数据表
产品代码
ATSAM4S-XPRO
211
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
12.9.1.3 Interrupt Control and State Register
Name:
SCB_ICSR
Access:
Read
/Write
Reset:
0x00
0000000
The SCB_ICSR provides a set-pending bit for the Non-Maskable Interrupt (NMI) exception, and set-pending and clear-
pending bits for the PendSV and SysTick exceptions.
It indicates:
It indicates:
• The exception number of the exception being processed, and whether there are preempted active exceptions,
• The exception number of the highest priority pending exception, and whether any interrupts are pending.
• NMIPENDSET: NMI Set-pending
Write:
PendSV set-pending bit.
Write:
0: No effect.
1: Changes NMI exception state to pending.
Read:
0: NMI exception is not pending.
1: NMI exception is pending.
As NMI is the highest-priority exception, the processor normally enters the NMI exception handler as soon as it registers a
PendSV set-pending bit.
Write:
0: No effect.
1: Changes NMI exception state to pending.
Read:
0: NMI exception is not pending.
1: NMI exception is pending.
As NMI is the highest-priority exception, the processor normally enters the NMI exception handler as soon as it registers a
write of 1 to this bit. Entering the handler clears this bit to 0. A read of this bit by the NMI exception handler returns 1 only if
the NMI signal is reasserted while the processor is executing that handler.
• PENDSVSET: PendSV Set-pending
Write:
0: No effect.
1: Changes PendSV exception state to pending.
Read:
0: PendSV exception is not pending.
1: PendSV exception is pending.
Writing a 1 to this bit is the only way to set the PendSV exception state to pending.
0: No effect.
1: Changes PendSV exception state to pending.
Read:
0: PendSV exception is not pending.
1: PendSV exception is pending.
Writing a 1 to this bit is the only way to set the PendSV exception state to pending.
31
30
29
28
27
26
25
24
NMIPENDSET
–
PENDSVSET
PENDSVCLR
PENDSTSET
PENDSTCLR
–
23
22
21
20
19
18
17
16
–
ISRPENDING
VECTPENDING
15
14
13
12
11
10
9
8
VECTPENDING
RETTOBASE
–
VECTACTIVE
7
6
5
4
3
2
1
0
VECTACTIVE