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Vol. 3A 4-9

PAGING

Figure 4-4 gives a summary of the formats of CR3 and the paging-structure entries with 32-bit paging. For the 
paging structure entries, it identifies separately the format of entries that map pages, those that reference other 
paging structures, and those that do neither because they are “not present”; bit 0 (P) and bit 7 (PS) are high-
lighted because they determine how such an entry is used.

Figure 4-2.  Linear-Address Translation to a 4-KByte Page using 32-Bit Paging

Figure 4-3.  Linear-Address Translation to a 4-MByte Page using 32-Bit Paging

0

Directory

Table

Offset

Page Directory

PDE with PS=0

CR3

Page Table

PTE

4-KByte Page

Physical Address

31

21

11

12

22

Linear Address

32

10

12

10

20

20

0

Directory

Offset

Page Directory

PDE with PS=1

CR3

4-MByte Page

Physical Address

31

21

22

Linear Address

10

22

32

18