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Release 1.0, 1 July 2002 F. Chapter F Memory Management Unit 99
TABLE F-6
describes the field encoding for
ISFSR.FT
.
Data <15> TM R/W Translation miss. When TM = 1, it signifies an occurrence of a mITLB miss
upon an instruction reference.
Data <13:7> FT<6:0> R/W Fault type. Saves and indicates an exact condition that caused the recorded
exception. See
TABLE F-6
for the field encoding.
In the IMMU, FT is valid only for an
instruction_access_exception
. The
ISFSR.FT always reads as 0 for a
fast_instruction_access_MMU_miss
and
reads 01
16
for an
instruction_access_exception
, since no other fault types
apply.
Data <5:4> CT<1:0> R/W Context type; Saves the context attribute for the reference that invokes an
exception. For nontranslating ASI or invalid ASI, ISFSR.CT =11
02
.
00
02
:Primary
01
02
:Reserved
10
02
: Nucleus
11
02
:Reserved
Data <3> PR R/W Privileged. Indicates the CPU privilege status during the instruction
reference that generates the exception. This field is valid when
ISFSR.FV =1.
Data <1> OW R/W Overwritten. Set when ISFSR.FV = 1 upon the detection of a exception.
This means that the fault valid bit is not yet cleared when another fault is
detected.
Data <0> FV R/W Fault valid. Set when the IMMU detects an exception. The bit is not set on
an IMMU miss. When the Fault Valid bit is not set, the values of the
remaining fields in the ISFSR are undefined, except for an IMMU miss.
TABLE F-6
Instruction Synchronous Fault Status Register FT (Fault Type) Field
FT<6:0> Error Description
01
16
Privilege violation. Set when TTE.P =1 and PSTATE.PRIV =0 for the
instruction reference.
02
16
Reserved
04
16
Reserved
08
16
Reserved
10
16
Reserved
20
16
Reserved, since there is no virtual hole.
40
16
Reserved, since there is no virtual hole.
TABLE F-5
I
-SFSR
Bit Description
Bits Field Name RW Description