System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-14
ID021414
Non-Confidential
4.3
AArch64 register descriptions
This section describes all the system registers, in register number order, when the system is in
the AArch64 Execution state.
Table 4-1 on page 4-3
to
Table 4-11 on page 4-12
provide
cross-references to individual registers.
4.3.1
Main ID Register, EL1
The MIDR_EL1 characteristics are:
Purpose
Provides identification information for the processor, including an
implementer code for the device and a device ID number.
Usage constraints
This register is accessible as follows:
Configurations
The MIDR_EL1 is:
•
Architecturally mapped to the AArch32 MIDR register. See
Main
ID Register
on page 4-157
.
•
Architecturally mapped to external MIDR_EL1 register.
Attributes
MIDR_EL1 is a 32-bit register.
Figure 4-1
shows the MIDR_EL1 bit assignments.
Figure 4-1 MIDR_EL1 bit assignments
Table 4-13
shows the MIDR_EL1 bit assignments.
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
RO
RO
RO
RO
RO
Variant
Implementer
31
23
20 19
16 15
4 3
0
Architecture
PartNum
Revision
24
Table 4-13 MIDR_EL1 bit assignments
Bits
Name
Function
[31:24]
Implementer
Indicates the implementer code. This value is:
0x41
ASCII character 'A' - implementer is ARM.
[23:20]
Variant
Indicates the variant number of the processor. This is the major revision number
x
in the r
x
part of the r
x
p
y
description of the product revision status. This value is:
0x0
r0p2.
[19:16]
Architecture
Indicates the architecture code. This value is:
0xF
Defined by CPUID scheme.
[15:4]
PartNum
Indicates the primary part number. This value is:
0xD03
Cortex-A53 processor.
[3:0]
Revision
Indicates the minor revision number of the processor. This is the minor revision number
y
in the p
y
part of
the r
x
p
y
description of the product revision status. This value is:
0x2
r0p2.