System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-200
ID021414
Non-Confidential
Table 4-196
shows the SCR bit assignments.
Table 4-196 SCR bit assignments
Bits
Name
Function
[31:14]
-
Reserved,
RES
0.
[13]
TWE
Trap
WFE
instructions. The possible values are:
0
WFE
instructions are not trapped. This is the reset value.
1
WFE
instructions executed in any mode other than Monitor mode are trapped to Monitor mode as
UNDEFINED
if the instruction would otherwise cause suspension of execution, that is if:
•
The event register is not set.
•
There is not a pending WFE wakeup event.
•
The instruction does not cause another exception.
[12]
TWI
Trap
WFI
instructions. The possible values are:
0
WFI
instructions are not trapped. This is the reset value.
1
WFI
instructions executed in any mode other than Monitor mode are trapped to Monitor mode as
UNDEFINED
if the instruction would otherwise cause suspension of execution.
[11:10]
-
Reserved,
RES
0.