System Control
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
4-26
ID073015
Non-Confidential
[27]
NMFI
RO
Non-maskable FIQ support.
The bit cannot be configured by software.
The
CFGNMFI
signal defines the reset value.
[26]
-
-
RAZ/SBZP.
[25]
EE bit
Banked
Determines how the E bit in the CPSR is set on an exception:
0
CPSR E bit is set to 0 on an exception
1
CPSR E bit is set to 1 on an exception.
This value also indicates the endianness of the translation table data for translation table lookups.
0
little-endian
1
big-endian.
The
CFGEND
signal defines the reset value.
[24]
-
-
RAZ/WI.
[23:22]
-
-
RAO/SBOP.
[21]
-
-
RAZ/WI.
[20:19]
-
-
RAZ/SBZP.
[18]
-
-
RAO/SBOP.
[17]
HA
-
RAZ/WI.
[16]
-
-
RAO/SBOP.
[15]
-
-
RAZ/SBZP.
[14]
RR
Secure
modify
only
Replacement strategy for the instruction cache, the BTAC, and the instruction and data micro TLBs.
This bit is RW in Secure state and RO in Non-secure state:
0
Random replacement. This is the reset value.
1
Round-robin replacement.
[13]
V
Banked
Vectors bit. This bit selects the base address of the exception vectors:
0
Normal exception vectors, base address
0x00000000
.
The Security Extensions are implemented, so this base address can be remapped.
1
High exception vectors, Hivecs, base address
0xFFFF0000
.
This base address is never remapped.
At reset the value for the secure version if this bit is taken from
VINITHI
.
[12]
I bit
Banked
Determines if instructions can be cached at any available cache level:
0
Instruction caching disabled at all levels. This is the reset value.
1
Instruction caching enabled.
[11]
Z bit
Banked
Enables program flow prediction:
0
Program flow prediction disabled. This is the reset value.
1
Program flow prediction enabled.
[10]
SW bit
Banked
SWP/SWPB enable bit:
0
SWP and SWPB are
UNDEFINED
.This is the reset value.
1
SWP and SWPB perform normally.
[9:7]
-
-
RAZ/SBZP.
[6:3]
-
-
RAO/SBOP.
Table 4-35 SCTLR bit assignments (continued)
Bits
Name
Access
Function