B.5
Other UNPREDICTABLE behaviors
This section describes other
UNPREDICTABLE
behaviors.
Table B-2 Other UNPREDICTABLE behaviors
Scenario
Description
CSSELR indicates a
cache that is not
implemented.
If CSSELR indicates a cache that is not implemented, then on a read of the CCSIDR the behavior is
CONSTRAINED UNPREDICTABLE
, and can be one of the following:
•
The CCSIDR read is treated as
NOP
.
•
The CCSIDR read is
UNDEFINED
.
•
The CCSIDR read returns an
UNKNOWN
value (preferred).
HDCR.HPMN is set to 0,
or to a value larger than
PMCR.N.
If HDCR.HPMN is set to 0, or to a value larger than PMCR.N, then the behavior in Non-secure EL0 and
EL1 is
CONSTRAINED UNPREDICTABLE
, and one of the following must happen:
•
The number of counters accessible is an
UNKNOWN
non-zero value less than PMCR.N.
•
There is no access to any counters.
For reads of HDCR.HPMN by EL2 or higher, if this field is set to 0 or to a value larger than PMCR.N, the
core must return a
CONSTRAINED UNPREDICTABLE
value that is one of:
•
PMCR.N.
•
The value that was written to HDCR.HPMN.
•
(The value that was written to HDCR.HPMN) modulo 2h, where h is the smallest number of bits
required for a value in the range 0 to PMCR.N.
B AArch32 UNPREDICTABLE Behaviors
B.5 Other UNPREDICTABLE behaviors
100236_0100_00_en
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