Digi NS9750 User Manual
Page 87
w w w . d i g i e m b e d d e d . c o m
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W o r k i n g w i t h t h e C P U
Figure 16 shows the format of the Fault Status registers. Table 24 describes the Fault
Status register bits.
Figure 16: Fault Status registers format
Table 25 shows the encodings used for the status field in the Fault Status register, and
indicates whether the domain field contains valid information. See "MMU faults and
CPU aborts" on page 95 for information about MMU aborts in Fault Address and Fault
Status registers.
Bits
Description
[31:9]
UNPREDICTABLE/SHOULD BE ZERO
[8]
Always reads as zero. Writes are ignored.
[7:4]
Specifies which of the 16 domains (D15–D0) was being accessed when a data
fault occurred.
[3:0]
Type of fault generated. (See "Memory Management Unit (MMU)," beginning
on page 78.)
Table 24: Fault Status register bit description
Priority
Source
Size
Status
Domain
Highest
Alignment
N/A
0b00x1
Invalid
External abort on translation
First level
Second level
0b1100
0b1110
Invalid
Valid
Translation
Section page
0b0101
0b0111
Invalid
Valid
Domain
Section page
0b1001
0b1011
Valid
Valid
Permission
Section page
0b1101
0b1111
Valid
Valid
Table 25: Fault Status register status field encoding
31
0
9
8
7
4
3
0
UNP/SBZ
Domain
Status