Register 56: Interrupt Control and State (INTCTRL), offset 0xD04
Note: This register can only be accessed from privileged mode.
The INCTRL register provides a set-pending bit for the NMI exception, and set-pending and
clear-pending bits for the PendSV and SysTick exceptions. In addition, bits in this register indicate
the exception number of the exception being processed, whether there are preempted active
exceptions, the exception number of the highest priority pending exception, and whether any interrupts
are pending.
When writing to INCTRL, the effect is unpredictable when writing a 1 to both the PENDSV and
UNPENDSV bits, or writing a 1 to both the PENDSTSET and PENDSTCLR bits.
Interrupt Control and State (INTCTRL)
Base 0xE000.E000
Offset 0xD04
Type RW, reset 0x0000.0000
16171819202122232425262728293031
VECPENDreservedISRPENDISRPREreserved
PENDSTCLRPENDSTSET
UNPENDSV
PENDSVreservedNMISET
ROROROROROROROROROWORWWORWRORORWType
0000000000000000Reset
0123456789101112131415
VECACTreservedRETBASEVECPEND
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
NMI Set Pending
DescriptionValue
On a read, indicates an NMI exception is not pending.
On a write, no effect.
0
On a read, indicates an NMI exception is pending.
On a write, changes the NMI exception state to pending.
1
Because NMI is the highest-priority exception, normally the processor
enters the NMI exception handler as soon as it registers the setting of
this bit, and clears this bit on entering the interrupt handler. 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.
0RWNMISET31
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0ROreserved30:29
PendSV Set Pending
DescriptionValue
On a read, indicates a PendSV exception is not pending.
On a write, no effect.
0
On a read, indicates a PendSV exception is pending.
On a write, changes the PendSV exception state to pending.
1
Setting this bit is the only way to set the PendSV exception state to
pending. This bit is cleared by writing a 1 to the UNPENDSV bit.
0RWPENDSV28
167June 18, 2014
Texas Instruments-Production Data
Tiva
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TM4C1294NCPDT Microcontroller