System Control
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
4-30
ID073015
Non-Confidential
•
common to Secure and Non-secure states.
Configurations
Available in all configurations.
Attributes
See the register summary in
.
shows the CPACR bit assignments.
Figure 4-10 CPACR bit assignments
shows the CPACR bit assignments.
31
24 23 22 21 20 19
0
cp11 cp10
ASEDIS
D32DIS
RAZ/WI
RAZ/WI
30 29
Table 4-37 CPACR bit assignments
Bits
Name
Function
[31]
ASEDIS
Disable Advanced SIMD Extension functionality:
0
All Advanced SIMD and VFP instructions execute normally
1
All Advanced SIMD instructions that are not VFP instructions are
UNDEFINED
.
See the
Cortex-A9 Floating-Point Unit Technical Reference Manual
and
Cortex-A9 NEON Media Processing
Engine Technical Reference Manual
for more information.
If implemented with VFP only, this bit is RAO/WI.
If implemented without both VFP and NEON, this bit is UNK/SBZP.
[30]
D32DIS
Disable use of D16-D31 of the VFP register file:
0
All VFP instructions execute normally
1
All VFP instructions are
UNDEFINED
if they access any of registers D16-D31.
See the
Cortex-A9 Floating-Point Unit Technical Reference Manual
and
Cortex-A9 NEON Media Processing
Engine Technical Reference Manual
for more information.
If implemented with VFP only, this bit is RAO/WI.
If implemented without both VFP and NEON, this bit is UNK/SBZP.
[29:24]
-
RAZ/WI.
[23:22]
cp11
Defines access permissions for the coprocessor. Access denied is the reset condition and is the behavior for
non-existent coprocessors.
b00
Access denied. This is the reset value. Attempted access generates an Undefined Instruction
exception.
b01
Privileged mode access only.
b10
Reserved.
b11
Privileged and User mode access.
[21:20]
cp10
Defines access permissions for the coprocessor. Access denied is the reset condition and is the behavior for
non-existent coprocessors.
b00
Access denied. This is the reset value. Attempted access generates an Undefined Instruction
exception.
b01
Privileged mode access only.
b10
Reserved.
b11
Privileged and User mode access.
[19:0]
-
RAZ/WI.