Filter
Top Products
Release 1.0, 1 July 2002 F. Chapter F Memory Management Unit
103
Multiple bits of DSFSR.FT may be set by a trap as long as the cause of the trap
matches multiply in
TABLE F-9
.
DSFSR is updated upon various traps, including f
ast_data_access_MMU_miss
,
data_access_exception
,
fast_data_access_protection
,
PA_watchpoint
,
VA_watchpoint
,
privileged_action
,
mem_address_not_aligned
, and
data_access_error
traps.
TABLE F-10
shows the detailed update policy of each field.
08
16
An attempt was made to access an alternate address space with an illegal ASI
value, an illegal VA, an invalid read/write attribute, or an illegally sized
operand. If the quad load ASI is used with the other opcode than LDDA, this bit
is set.
Note: Since an illegal ASI check is done prior to a TTE unmatch check,
DSFSR.FT<3> = 1 causes the value of other bits of DSFSR.FT to be
undetermined and generates a
data_access_exception
exception (which
otherwise has lower priority than
fast_data_access_MMU_miss
).
Note, too, that a reference to an internal ASI may generate a
mem_address_not_aligned exception.
10
16
Access other than nonfaulting load was made to a page marked NFO. This bit is
zero for internal ASI accesses.
20
16
Reserved, since there is no virtual hole.
40
16
Reserved, since there is no virtual hole.
TABLE F-10
DSFSR
Update Policy
Field
TLB#,
index
FV OW
W, PR,
NF, CT
1
FT TM ASI
UE, UPA,
mDTLB, NC
2
, E
2
DSFAR
Fresh fault or miss
3
Miss MMU miss
—
00 V
—
1
——
V
Exception
Access exception
—
10 V V0V
—
V
Faults
Access protection
—
10 V
—
0V
—
V
PA watchpoint
—
10 V
—
0V
—
V
VA watchpoint
—
10 V
—
0V
—
V
Privileged action
4
—
10 V
—
0V
—
V
Access misaligned
—
10 V
—
0V
—
-V
Access error
V
5
10 V
—
0V V V
Overwrite Policy
6
Exception on fault K 1 1 U U K U K U
Fault on exception
U
4
11 U KKU U U
Exception on miss
7
K1K UU1U K U
Fault on miss
U
4
1K U K1U U U
TABLE F-9
MMU Synchronous Fault Status Register FT (Fault Type) Field (Continued)
FT<6:0> Error Description