Digi NS9750 User Manual

Page 118

Advertising
background image

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

9 4

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

If a small page descriptor is included in a fine page table, the upper two bits of the
page index and low-order two bits of the fine page table index overlap. Each fine
page table entry for a small page must be duplicated four times.

Translating tiny page references

Figure 35: Tiny page translation from a fine 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

Fine page table base address

2

1 1

1

3

4

5

Domain 1

31

0

Fine page table base address

Level two

table index

10 9

Modified virtual address

8

11

12

1

2

11

12

31

10 9

6 5 4 3 2 1 0

0

0

L2 table index

1

1

B

C

AP

Page base address

Page base address

31

0

10 9

Page index

Physical address

Second-level descriptor

Advertising