System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-82
ID021414
Non-Confidential
Figure 4-42 CPTR_EL3 bit assignments
Table 4-81
shows the CPTR_EL3 bit assignments.
To access the CPTR_EL3:
MRS <Xt>, CPTR_EL3 ; Read CPTR_EL3 into Xt
MSR CPTR_EL3, <Xt> ; Write Xt to CPTR_EL3
4.3.47
Monitor Debug Configuration Register, EL3
The MDCR_EL3 characteristics are:
Purpose
Provides configuration options for Security to self-hosted debug.
Usage constraints
This register is accessible as follows:
Configurations
MDCR_EL3 is mapped to AArch32 register SDCR. See
Secure Debug
Control Register
on page 4-204
.
31
0
RES
0
RES
1
TFP
10 9
11
30
TCPAC
19
20
21
RES
0
TTA
12
13
14
RES
1
RES
0
Table 4-81 CPTR_EL3 bit assignments
Bits
Name
Function
[31]
TCPAC
This causes a direct access to the CPACR_EL1 from EL1 or the CPTR_EL2 from EL2 to trap to EL3 unless it
is trapped at EL2. The possible values are:
0
Does not cause access to the CPACR_EL1 or CPTR_EL2 to be trapped.
1
Causes access to the CPACR_EL1 or CPTR_EL2 to be trapped.
[30:21]
-
Reserved,
RES
0.
[20]
TTA
Trap Trace Access.
Not implemented.
RES
0.
[19:14]
-
Reserved,
RES
0.
[13:12]
-
Reserved,
RES
1.
[11]
-
Reserved,
RES
0.
[10]
TFP
This causes instructions that access the registers associated with Advanced SIMD or floating-point execution to
trap to EL3 when executed from any exception level, unless trapped to EL1 or EL2. The possible values are:
0
Does not cause any instruction to be trapped.This is the reset value if the Advanced SIMD and
Floating-point Extension is not implemented.
1
Causes any instructions that use the registers associated with Advanced SIMD or floating-point
execution to be trapped. This is always the value if the Advanced SIMD and Floating-point
Extension is not implemented.
[9:0]
-
Reserved,
RES
1.
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
-
-
RW
RW