
M0A21/M0A23 Series
May 06, 2022
Page
174
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
[26]
PENDSTSET
SysTick Exception Set-pending Bit
Write Operation:
0 = No effect.
1 = Changes SysTick exception state to pending.
Read Operation:
0 = SysTick exception is not pending.
1 = SysTick exception is pending.
[25]
PENDSTCLR
SysTick Exception Clear-pending Bit
Write Operation:
0 = No effect.
1 = Removes the pending state from the SysTick exception.
Note:
This is a write only bit. To clear the
PENDST bit, you must “write 0 to PENDSTSET and write 1
to PENDSTRTC_CAL” at the same time.
[24]
Reserved
Reserved.
[23]
ISRPREEMPT
Interrupt Preempt Bit (Read Only)
If set, a pending exception will be serviced on exit from the debug halt state.
[22]
ISRPENDING
Interrupt Pending Flag, Excluding NMI and Faults (Read Only)
0 = Interrupt not pending.
1 = Interrupt pending.
[21:18]
Reserved
Reserved.
[17:12]
VECTPENDING
Number of the Highest Pended Exception
Indicate the Exception Number of the Highest Priority Pending Enabled Exception
0 = no pending exceptions.
Nonzero = the exception number of the highest priority pending enabled exception.
The value indicated by this field includes the effect of the BASEPRI and FAULTMASK registers, but
not any effect of the PRIMASK register.
[11]
RETTOBASE
Preempted Active Exceptions Indicator
Indicate whether There are Preempted Active Exceptions
0 = there are preempted active exceptions to execute.
1 = there are no active exceptions, or the currently-executing exception is the only active exception.
[10:6]
Reserved
Reserved.
[5:0]
VECTACTIVE
Number of the Current Active Exception
0 = Thread mode.
Non-zero = The exception number of the currently active exception.