B1.47
Domain Access Control Register
The DACR characteristics are:
Purpose
Defines the access permission for each of the sixteen memory domains.
Usage constraints
This register is accessible as follows:
EL0
(NS)
EL0
(S)
EL1
(NS)
EL1
(S)
EL2 EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
RW
RW RW RW
RW
Configurations
DACR (NS) is architecturally mapped to AArch64 register DACR32_EL2. See
.
If EL3 is using AArch32, there are separate Secure and Non-secure instances of this register.
If EL3 is using AArch32, write access to DACR(S) is disabled when the
CP15SDISABLE2
signal is asserted HIGH.
DACR has no function when TTBCR.EAE is set to 1 to select the Long-descriptor translation
table format.
Attributes
DACR is a 32-bit register.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
D15 D14 D13 D12 D11 D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Figure B1-11 DACR bit assignments
D<n>, bits [2n+1:2n], for n = 0 to 15, [31:0]
Domain
n
access permission, where
n
= 0 to 15. Permitted values are:
0b00
No access. Any access to the domain generates a Domain fault.
0b01
Client. Accesses are checked against the permission bits in the translation tables.
0b11
Manager. Accesses are not checked against the permission bits in the translation tables.
The value
0b10
is reserved.
To access the DACR:
MRC p15, 0, <Rt>, c3, c0, 0 ; Read DACR into Rt
MCR p15, 0, <Rt>, c3, c0, 0 ; Write Rt to DACR
Register access is encoded as follows:
Table B1-41 DACR access encoding
coproc opc1 CRn CRm opc2
1111
000
0011 0000 000
B1 AArch32 system registers
B1.47 Domain Access Control Register
100236_0100_00_en
Copyright © 2015–2017, 2019 Arm Limited or its affiliates. All rights
reserved.
B1-221
Non-Confidential
Summary of Contents for Cortex-A35
Page 4: ......
Page 18: ......
Page 26: ......
Page 27: ...Part A Functional Description ...
Page 28: ......
Page 145: ...Part B Register Descriptions ...
Page 146: ......
Page 573: ...Part C Debug ...
Page 574: ......
Page 845: ...Part D Appendices ...
Page 846: ......