B2.22
CPTR_EL3, Architectural Feature Trap Register, EL3
The CPTR_EL3 controls trapping to EL3 of access to CPACR_EL1, CPTR_EL2, trace functionality and
registers associated with Advanced SIMD and floating-point execution.
It also controls EL3 access to trace functionality and registers associated with Advanced SIMD and
floating-point execution.
Bit field descriptions
CPTR_EL3 is a 32-bit register, and is part of the Security registers functional group.
31 30
21 20 19
11 10 9
0
TCPAC
TTA
TFP
RES
0
Figure B2-18 CPTR_EL3 bit assignments
TTA, [20]
Trap Trace Access.
Not implemented.
RES0
.
TFP, [10]
Traps all accesses to SVE, Advanced SIMD and floating-point functionality to EL3. This
applies to all Exception levels, both Security states, and both Execution states. The possible
values are:
0
Does not cause any instruction to be trapped. This is the reset value.
1
Any attempt at any Exception level to execute an instruction that uses the registers that
are associated with SVE, Advanced SIMD and floating-point is trapped to EL3,
subject to the exception prioritization rules.
Configurations
There are no configuration notes.
Bit fields and details that are not provided in this description are architecturally defined. See the
Arm
®
Architecture Reference Manual Armv8, for Armv8-A architecture profile
.
B2 AArch64 system registers
B2.22 CPTR_EL3, Architectural Feature Trap Register, EL3
100798_0300_00_en
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