ST STM32F3 Series

PM0214 Rev 10 225/262
PM0214 Core peripherals
261
4.4.3 Interrupt control and state register (ICSR)
Address offset: 0x04
Reset value: 0x0000 0000
Required privilege: Privileged
The ICSR:
• Provides:
– A set-pending bit for the Non-Maskable Interrupt (NMI) exception
– Set-pending and clear-pending bits for the PendSV and SysTick exceptions
• Indicates:
– The exception number of the exception being processed
– Whether there are preempted active exceptions
– The exception number of the highest priority pending exception
– Whether any interrupts are pending.
Caution: When you write to the ICSR, the effect is unpredictable if you:
• Write 1 to the PENDSVSET bit and write 1 to the PENDSVCLR bit
• Write 1 to the PENDSTSET bit and write 1 to the PENDSTCLR bit.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
NMIPENDSET
Reserved
PENDSVSET
PENDSVCLR
PENDSTSET
PENDSTCLR
Reserved
ISRPENDING
Reserved
VECTPENDING[6:4]
rw rw w rw w r r r r
1514131211109876543210
VECTPENDING[3:0]
RETOBASE
Reserved
VECTACTIVE[8:0]
rrrrr rwrwrwrwrwrwrwrwrw
Bit 31 NMIPENDSET: NMI set-pending bit.
Write:
0: No effect
1: Change NMI exception state to pending.
Read:
0: NMI exception is not pending
1: NMI exception is pending
Because NMI is the highest-priority exception, normally the processor enter the NMI
exception handler as soon as it registers a write of 1 to this bit, and 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.
Bits 30:29 Reserved