System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-76
ID021414
Non-Confidential
To access the SCTLR_EL3:
MRS <Xt>, SCTLR_EL3 ; Read SCTLR_EL3 into Xt
MSR SCTLR_EL3, <Xt> ; Write Xt to SCTLR_EL3
4.3.42
Secure Configuration Register
The SCR_EL3 characteristics are:
Purpose
Defines the configuration of the security state. SCR_EL3 specifies:
•
Security state of EL0 and EL1, either Secure or Non-secure.
•
Register width at lower exception levels.
•
The exception level that the processor takes exceptions at, if an IRQ,
FIQ, or external abort occurs.
SCR_EL3 is part of the Security registers functional group.
Usage constraints
This register is accessible as follows:
Configurations
SCR_EL3 is mapped to AArch32 register SCR. See
Secure Configuration
Register
on page 4-199
.
Attributes
SCR_EL3 is a 32-bit register.
Figure 4-38
shows the SCR_EL3 bit assignments.
Figure 4-38 SCR_EL3 bit assignments
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
-
-
RW
RW
31
10 9 8 7 6
4 3 2 1 0
RES
0
SIF
HCE
RW
ST
EA
FIQ
IRQ
NS
RES
0
TWI
TWE
11
12
13
14
SMD
RES
1
5