System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-205
ID021414
Non-Confidential
Table 4-199
shows the SDCR bit assignments
To access the SDCR:
MRC p15,0,<Rt>,c1,c3,1 ; Read SDCR into Rt
MCR p15,0,<Rt>,c1,c3,1 ; Write Rt to SDCR
4.5.34
Hyp Auxiliary Control Register
The HACTLR characteristics are:
Purpose
Controls write access to
IMPLEMENTATION
DEFINED
registers in
Non-secure EL1 modes, such as CPUACTLR, CPUECTLR, L2CTLR,
L2ECTLR and L2ACTLR.
Table 4-199 SDCR bit assignments
Bits
Name
Function
[31:22]
-
Reserved,
RES
0.
[21]
EPMAD
External debugger access to Performance Monitors registers disabled. This disables access to these registers by
an external debugger:
0
Access to Performance Monitors registers from external debugger is permitted. This is the reset
value.
1
Access to Performance Monitors registers from external debugger is disabled, unless overridden
by authentication interface.
[20]
EDAD
External debugger access to breakpoint and watchpoint registers disabled. This disables access to these registers
by an external debugger:
0
Access to breakpoint and watchpoint registers from external debugger is permitted. This is the
reset value.
1
Access to breakpoint and watchpoint registers from external debugger is disabled, unless
overridden by authentication interface.
[19:18]
-
Reserved,
RES
0.
[17]
SPME
Secure performance monitors enable. This allows event counting in Secure state:
0
Event counting prohibited in Secure state, unless overridden by the authentication interface.
This is the reset value.
1
Event counting allowed in Secure state.
[16]
-
Reserved,
RES
0.
[15:14]
SPD
AArch32 secure privileged debug. Enables or disables debug exceptions in Secure state, other than Software
breakpoint instructions. The possible values are:
0b00
Legacy mode. Debug exceptions from Secure EL1 are enabled by the authentication interface.
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 value
0b01
is reserved.
If debug exceptions from Secure EL1 are enabled, then debug exceptions from Secure EL0 are also enabled.
Otherwise, debug exceptions from Secure EL0 are enabled only if SDER32_EL3.SUIDEN is 1.
SPD is ignored in Non-secure state. Debug exceptions from Software breakpoint instruction debug events are
always enabled.
[13:0]
-
Reserved,
RES
0.