Digi NS9750 - Manual (Page 123)

w w w . d i g i e m b e d d e d . c o m 9 9
W o r k i n g w i t h t h e C P U
Fault checking sequence
The sequence the MMU uses to check for access faults is different for sections and
pages. Figure 36 shows the sequence for both types of access.
0 0 1 0 Read only Read only
0 0 0 1 Read only Read only
0 0 1 1 UNPREDICTABLE UNPREDICTABLE
0 1 x x Read/write No access
1 0 x x Read/write Read only
1 1 x x Read/write Read/write
AP S R Privileged permissions User permissions
Table 42: Interpreting access permission (AP) bits