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CONTENTS
Paragraph
Number
Title
Page
Number
Contents
xiii
5.4.3
5.4.3.1
5.4.3.2
5.4.3.2.1
5.4.3.2.2
5.4.3.2.3
5.4.4
5.4.5
5.4.5.1
5.4.5.2
5.4.5.3
5.4.6
5.4.7
TLB Description........................................................................................... 5-25
TLB Organization and Operation............................................................. 5-25
TLB Invalidation ...................................................................................... 5-27
tlbie
Instruction .................................................................................... 5-27
tlbsync
Instruction................................................................................ 5-29
Synchronization Requirements for tlbie and tlbsync............................ 5-30
Page Address Translation Summary............................................................. 5-31
Page Table Search Operation........................................................................ 5-33
Conditions for a Page Table Search Operation......................................... 5-33
AltiVec Line Fetch Skipping.................................................................... 5-34
Page Table Search Operation Flow .......................................................... 5-34
Page Table Updates ...................................................................................... 5-37
Segment Register Updates............................................................................ 5-38
Chapter 6
Instruction Timing
6.1
6.2
6.3
6.3.1
6.3.2
6.3.2.1
6.3.2.2
6.3.2.3
6.3.3
6.3.3.1
6.3.4
6.3.4.1
6.3.4.2
6.4
6.4.1
6.4.1.1
Terminology and Conventions............................................................................ 6-2
Instruction Timing Overview.............................................................................. 6-4
Timing Considerations........................................................................................ 6-9
General Instruction Flow................................................................................ 6-9
Instruction Fetch Timing .............................................................................. 6-12
Cache Arbitration...................................................................................... 6-12
Cache Hit.................................................................................................. 6-12
Cache Miss................................................................................................ 6-15
Memory Subsystem-Specific Pipeline Diagrams......................................... 6-17
L2 Cache Access Timing Considerations (MPX Bus Only).................... 6-19
Instruction Dispatch and Completion Considerations.................................. 6-20
Rename Register Operation...................................................................... 6-21
Instruction Serialization............................................................................ 6-21
Execution Unit Timings.................................................................................... 6-22
Branch Processing Unit Execution Timing .................................................. 6-22
Branch Folding and Removal of Fall-Through Branch
Instructions ........................................................................................... 6-23
Branch Instructions and Completion........................................................ 6-24
Branch Prediction and Resolution............................................................ 6-25
Static Branch Prediction....................................................................... 6-27
Predicted Branch Timing Examples..................................................... 6-27
Integer Unit Execution Timing..................................................................... 6-29
Floating-Point Unit Execution Timing......................................................... 6-29
Effect of Floating-Point Exceptions on Performance................................... 6-30
6.4.1.2
6.4.1.3
6.4.1.3.1
6.4.1.3.2
6.4.2
6.4.3
6.4.4