B2.54
AArch64 Processor Feature Register 0, EL1
The ID_AA64PFR0_EL1 characteristics are:
Purpose
Provides additional information about implemented processor features in AArch64.
The optional Advanced SIMD and floating-point support is not included in the base product of
the processor. Arm requires licensees to have contractual rights to obtain the Advanced SIMD
and floating-point support.
Usage constraints
This register is accessible as follows:
EL0 EL1
(NS)
EL1
(S)
EL2 EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
RO
RO
RO
RO
RO
Configurations
ID_AA64PFR0_EL1 is architecturally mapped to external register EDPFR.
Attributes
ID_AA64PFR0_EL1 is a 64-bit register.
63
0
RES
0
4 3
8 7
12 11
16 15
EL3
handling
EL2
handling
EL1
handling
EL0
handling
FP
AdvSIMD
20 19
24 23
GIC
28 27
Figure B2-28 ID_AA64PFR0_EL1 bit assignments
[63:28]
Reserved,
RES0
.
GIC, [27:24]
GIC CPU interface:
0x0
GIC CPU interface is disabled, GICCDISABLE is HIGH, or not implemented.
0x1
GIC CPU interface is implemented and enabled, GICCDISABLE is low.
AdvSIMD, [23:20]
Advanced SIMD. The possible values are:
0x0
Advanced SIMD is implemented.
0xF
Advanced SIMD is not implemented.
The FP and AdvSIMD both take the same value, as both must be implemented, or neither.
FP, [19:16]
Floating-point. The possible values are:
0x0
Floating-point is implemented.
0xF
Floating-point is not implemented.
The FP and AdvSIMD both take the same value, as both must be implemented, or neither.
EL3 handling, [15:12]
B2 AArch64 system registers
B2.54 AArch64 Processor Feature Register 0, EL1
100236_0100_00_en
Copyright © 2015–2017, 2019 Arm Limited or its affiliates. All rights
reserved.
B2-450
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: ......