System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-85
ID021414
Non-Confidential
To access the MDCR_EL3:
MRS <Xt>, MDCR_EL3 ; Read EL3 Monitor Debug Configuration Register
MSR MDCR_EL3, <Xt> ; Write EL3 Monitor Debug Configuration Register
[19:18]
-
Reserved,
RES
0.
[17]
SPME
Secure performance monitors enable. This enables event counting exceptions from Secure state. The possible
values are:
0
Event counting prohibited in Secure state. This is the reset value.
1
Event counting allowed in Secure state.
[16]
SDD
AArch64 secure debug disable. Disables Software debug exceptions from Secure state if Secure EL1 is using
AArch64, other than from Software breakpoint instructions. The possible values are:
0
Debug exceptions from Secure EL0 are enabled, and debug exceptions from Secure EL1 are
enabled if MDSCR_EL1.KDE is 1 and PSTATE.D is 0.
1
Debug exceptions from all exception levels in Secure state are disabled.
The reset value is
UNKNOWN
.
[15:14]
SPD32
AArch32 secure privileged debug. Enables or disables debug exceptions from Secure state if Secure EL1 is
using AArch32, other than Software breakpoint instructions. The possible values are:
0b00
Legacy mode. Debug exceptions from Secure EL1 are enabled only if
AArch32SelfHostedSecurePrivilegedInvasiveDebugEnabled()
.
0b01
Reserved.
0b10
Secure privileged debug disabled. Debug exceptions from Secure EL1 are disabled.
0b11
Secure privileged debug enabled. Debug exceptions from Secure EL1 are enabled.
The reset value is
UNKNOWN
.
[13:11]
-
Reserved,
RES
0.
[10]
TDOSA
Trap accesses to the OS debug system registers, OSLAR_EL1, OSLSR_EL1, OSDLR_EL1, and
DBGPRCR_EL1 OS.
0
Accesses are not trapped.
1
Accesses to the OS debug system registers are trapped to EL3.
The reset value is
UNKNOWN
.
[9]
TDA
Trap accesses to the remaining sets of debug registers to EL3.
0
Accesses are not trapped.
1
Accesses to the remaining debug system registers are trapped to EL3.
The reset value is
UNKNOWN
.
[8:7]
-
Reserved,
RES
0.
[6]
TPM
Trap Performance Monitors accesses. The possible values are:
0
Accesses are not trapped.
1
Accesses to the Performance Monitor registers are trapped to EL3.
The reset value is
UNKNOWN
.
[5:0]
-
Reserved,
RES
0.
Table 4-82 MDCR_EL3 bit assignments (continued)
Bits
Name
Function