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M68040 USER’S MANUAL
MOTOROLA
TABLE OF CONTENTS (Continued)
Paragraph
Page
Number
Title
Number
Section 4
Instruction and Data Caches
4.1
Cache Operation ................................................................................... 4-2
4.2
Cache Management.............................................................................. 4-5
4.3
Caching Modes ..................................................................................... 4-6
4.3.1
Cachable Accesses ........................................................................... 4-6
4.3.1.1
Write-Through Mode ......................................................................4-6
4.3.1.2
Copyback Mode ............................................................................. 4-6
4.3.2
Cache-Inhibited Accesses ................................................................. 4-7
4.3.3
Special Accesses .............................................................................. 4-7
4.4
Cache Protocol ..................................................................................... 4-7
4.4.1
Read Miss ......................................................................................... 4-8
4.4.2
Write Miss .......................................................................................... 4-8
4.4.3
Read Hit ............................................................................................ 4-8
4.4.4
Write Hit ............................................................................................. 4-8
4.5
Cache Coherency ................................................................................. 4-9
4.6
Memory Accesses for Cache Maintenance........................................... 4-11
4.6.1
Cache Filling...................................................................................... 4-11
4.6.2
Cache Pushes ................................................................................... 4-13
4.7
Cache Operation Summary................................................................... 4-13
4.7.1
Instruction Cache............................................................................... 4-14
4.7.2
Data Cache........................................................................................ 4-15
Section 5
Signal Description
5.1
Address Bus (A31–A0) ......................................................................... 5-4
5.2
Data Bus (D31–D0) ...............................................................................5-5
5.3
Transfer Attribute Signals...................................................................... 5-5
5.3.1
Transfer Type (TT1, TT0) .................................................................. 5-5
5.3.2
Transfer Modifier (TM2–TM0) ........................................................... 5-6
5.3.3
Transfer Line Number (TLN1, TLN0)................................................. 5-6
5.3.4
User-Programmable Attributes (UPA1, UPA0) .................................. 5-7
5.3.5
Read/Write (R/W) .............................................................................. 5-7
5.3.6
Transfer Size (SIZ1, SIZ0) ................................................................ 5-7
5.3.7
Lock (LOCK) ...................................................................................... 5-7
5.3.8
Lock End (LOCKE) ............................................................................ 5-7
5.3.9
Cache Inhibit Out (CIOUT) ................................................................ 5-8
5.4
Bus Transfer Control Signals ................................................................ 5-8
5.4.1
Transfer Start (TS) ............................................................................. 5-8
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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