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MPC850 Integrated Communications Microprocessor Users Manual
MOTOROLA
CONTENTS
Paragraph
Number
Title
Page
Number
7.5.5
7.6
7.6.1
7.6.2
7.6.3
7.6.3.1
7.6.3.2
7.6.4
7.6.4.1
7.6.4.2
7.6.5
7.6.6
7.7
7.8
7.8.1
7.8.2
Updating Code And Memory Region Attributes............................................7-24
Data Cache Operation.........................................................................................7-24
Data Cache Load Hit......................................................................................7-25
Data Cache Read Miss....................................................................................7-25
Write-Through Mode......................................................................................7-26
Data Cache Store Hit in Write-Through Mode..........................................7-26
Data Cache Store Miss in Write-Through Mode........................................7-26
Write-Back Mode...........................................................................................7-26
Data Cache Store Hit in Write-Back Mode................................................7-26
Data Cache Store Miss in Write-Back Mode.............................................7-27
Data Accesses to Caching-Inhibited Memory Regions..................................7-27
Atomic Memory References...........................................................................7-28
Cache Initialization after Reset...........................................................................7-29
Debug Support....................................................................................................7-29
Instruction and Data Cache Operation in Debug Mode .................................7-29
Instruction and Data Cache Operation with a Software Monitor Debugger..7-30
Chapter 8
Memory Management Unit
8.1
8.2
8.3
8.3.1
8.3.2
8.3.3
8.4
8.5
8.6
8.7
8.7.1
8.7.2
8.8
8.8.1
8.8.2
8.8.3
8.8.4
8.8.5
8.8.6
8.8.7
8.8.8
8.8.9
Features.................................................................................................................8-1
PowerPC Architecture Compliance......................................................................8-2
Address Translation..............................................................................................8-3
Translation Disabled.........................................................................................8-3
Translation Enabled..........................................................................................8-3
TLB Operation..................................................................................................8-5
Using Access Protection Groups..........................................................................8-6
Protection Resolution Modes................................................................................8-7
Memory Attributes ...............................................................................................8-8
Translation Table Structure..................................................................................8-9
Level-One Descriptor.....................................................................................8-13
Level-Two Descriptor ....................................................................................8-14
Programming Model...........................................................................................8-14
IMMU Control Register (MI_CTR)...............................................................8-16
DMMU Control Register (MD_CTR)............................................................8-17
IMMU/DMMU Effective Page Number Register (Mx_EPN).......................8-18
IMMU Tablewalk Control Register (MI_TWC)............................................8-18
DMMU Tablewalk Control Register (MD_TWC).........................................8-19
IMMU Real Page Number Register (MI_RPN).............................................8-20
DMMU Real Page Number Register (MD_RPN)..........................................8-22
MMU Tablewalk Base Register (M_TWB)...................................................8-23
MMU Current Address Space ID Register (M_CASID) ...............................8-23