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Digi NS9750 User Manual

Page 116

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M e m o r y M a n a g e m e n t U n i t ( M M U )

9 2

N S 9 7 5 0 H a r d w a r e R e f e r e n c e

Figure 33: Large page translation from a coarse page table

Because the upper four bits of the page index and low-order four bits of the coarse
page table index overlap, each coarse page table entry for a large page must be
duplicated 16 times (in consecutive memory locations) in the coarse page table.

31

14 13

0

Translation base

1

Translation table base

31

14 13

0

Translation base

2

Table index

0 0

31

20 19

0

Table index

Page index

First-level descriptor

31

0

Coarse page table base address

2

0 1

1

3

4

5

Domain 1

31

0

Coarse page table base address

table index

1615

12 11

Modified virtual address

8

9

10

1

2

9

10

31

1615

12 1110 9 8 7 6 5 4 3 2 1 0

0

0

L2 table index

0 1

B

C

AP0

AP1

AP2

AP3

Page base address

Page base address

31

0

16 15

Page index

Physical address

Second-level descriptor