Use the Interrupt Control State Register to set a pending Non-Maskable Interrupt (NMI), set or clear a pending PendSV, set or clear a pending SysTick, check for pending exceptions, check the vector number of the highest priority pended exception, check the vector number of the active exception.
| VECTACTIVE | Active exception number field. Reset clears the VECTACTIVE field. |
| VECTPENDING | Indicates the exception number for the highest priority pending exception: 0 = no pending exceptions. Non zero = The pending state includes the effect of memory-mapped enable and mask registers. It does not include the PRIMASK special-purpose register qualifier. |
| ISRPENDING | External interrupt pending flag |
| ISRPREEMPT | The system can only access this bit when the core is halted. It indicates that a pending interrupt is to be taken in the next running cycle. If C_MASKINTS is clear in the Debug Halting Control and Status Register, the interrupt is serviced. |
| PENDSTCLR | SysTick exception clear-pending bit. Write: 0 = No effect. 1 = Removes the pending state from the SysTick exception. This bit is WO. On a register read its value is Unknown. |
| PENDSTSET | SysTick exception set-pending bit. Write: 0 = No effect. 1 = Changes SysTick exception state to pending. Read: 0 = SysTick exception is not pending. 1 = SysTick exception is pending. |
| PENDSVCLR | PendSV clear-pending bit. Write: 0 = No effect. 1 = Removes the pending state from the PendSV exception. |
| PENDSVSET | PendSV set-pending bit. Write: 0 = No effect. 1 = Changes PendSV exception state to pending. Read: 0 = PendSV exception is not pending. 1 = PendSV exception is pending. Writing 1 to this bit is the only way to set the PendSV exception state to pending. |
| NMIPENDSET | Setting this bit will activate an NMI. Since NMI is the highest priority exception, it will activate as soon as it is registered. NMI 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. Because NMI is the highest-priority exception, normally the processor enters the NMI exception handler as soon as it detects a write of 1 to this bit. Entering the handler then clears this bit to 0. This means 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. |