System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-18
ID021414
Non-Confidential
Configurations
ID_PFR0_EL1 is architecturally mapped to AArch32 register ID_PFR0.
See
Processor Feature Register 0
on page 4-160
.
Attributes
ID_PFR0_EL1 is a 32-bit register.
Figure 4-4
shows the ID_PFR0_EL1 bit assignments.
Figure 4-4 ID_PFR0_EL1 bit assignments
Table 4-19
shows the ID_PFR0_EL1 bit assignments.
To access the ID_PFR0_EL1:
MRS <Xt>, ID_PFR0_EL1 ; Read ID_PFR0_EL1 into Xt
Register access is encoded as follows:
4.3.5
AArch32 Processor Feature Register 1
The ID_PFR1_EL1 characteristics are:
Purpose
Provides information about the programmers model and architecture
extensions supported by the processor.
Usage constraints
This register is accessible as follows:
31
12 11
8 7
0
RES
0
State2
State1
16 15
4 3
State0
State3
Table 4-19 ID_PFR0_EL1 bit assignments
Bits
Name
Function
[31:16]
-
Reserved,
RES
0.
[15:12]
State3
Indicates support for
Thumb Execution Environment
(T32EE) instruction set. This value is:
0x0
Processor does not support the T32EE instruction set.
[11:8]
State2
Indicates support for Jazelle. This value is:
0x1
Processor supports trivial implementation of Jazelle.
[7:4]
State1
Indicates support for T32 instruction set. This value is:
0x3
Processor supports T32 encoding after the introduction of Thumb-2 technology, and for all 16-bit
and 32-bit T32 basic instructions.
[3:0]
State0
Indicates support for A32 instruction set. This value is:
0x1
A32 instruction set implemented.
Table 4-20 REVIDR access encoding
op0
op1
CRn
CRm
op2
1111
000
0000
0001
000
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
RO
RO
RO
RO
RO