
MOTOROLA
M68040 USER'S MANUAL
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POINTER TABLE ADDRESS
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ROOT TABLE DESCRIPTOR (ROOT LEVEL)
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PAGE TABLE ADDRESS
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PAGE TABLE ADDRESS
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8K POINTER TABLE DESCRIPTOR (POINTER LEVEL)
Figure 3-11. Table Descriptor Formats
3.2.2.2 PAGE DESCRIPTORS.
Figure 3-12 illustrates the page descriptors for both
4-Kbyte and 8-Kbyte page sizes. Refer to
Section 4 Instruction and Data Caches
for
details concerning caching page descriptors.
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PHYSICAL ADDRESS
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4K PAGE DESCIPTOR (PAGE LEVEL)
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8K PAGE DESCRIPTOR (PAGE LEVEL)
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DESCRIPTOR ADDRESS
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INDIRECT PAGE DESCRIPTOR (PAGE LEVEL)
Figure 3-12. Page Descriptor Formats
3.2.2.3 DESCRIPTOR FIELD DEFINITIONS.
The field definitions for the table- and page-
level descriptors are listed in alphabetical order:
CM—Cache Mode
This field selects the cache mode and accesses serialization as follows:
00 = Cachable, Write-through
01 = Cachable, Copyback
10 = Noncachable, Serialized
11 = Noncachable
Section 4 Instruction and Data Caches
provides detailed information on caching
modes, and
Section 7 Bus Operation
provides information on serialization.