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Chapter 9 Memory Organization. Chapter Outline. Hierarchical Memory Systems Cache Memory Virtual Memory Pentium/Windows Memory System. Memory Hierarchy. Associative Memory. Data Register. Associative Memory. Data Register Mask Register. Associative Memory. Data Register Mask Register
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Chapter Outline • Hierarchical Memory Systems • Cache Memory • Virtual Memory • Pentium/Windows Memory System
Associative Memory • Data Register
Associative Memory • Data Register • Mask Register
Associative Memory • Data Register • Mask Register • Match Register
Data Lines/Blocks • Multiple consecutive words form a line
Data Lines/Blocks • Multiple consecutive words form a line • All data in a line is moved together
Data Lines/Blocks • Multiple consecutive words form a line • All data in a line is moved together • Takes advantage of locality of reference
Drawbacks of Direct Mapped Cache 0000 0000 0000 0000: JUMP 1000H 0001 0000 0000 0000: JUMP 0000H
Data Replacement Policies • FIFO
Data Replacement Policies • FIFO • LRU
Data Replacement Policies • FIFO • LRU • Random
Writing Data to Cache • Write back • Write through • Write allocate • Write no-allocate
Cache Performance • Hits and misses
Cache Performance • Hits and misses • Hit ratio
Cache Performance • Hits and misses • Hit ratio • Average memory access time
Virtual Memory • Memory Management Unit (MMU)
Virtual Memory • Memory Management Unit (MMU) • Swap disk/file
Virtual Memory • Memory Management Unit (MMU) • Swap disk/file • Logical address
Virtual Memory • Memory Management Unit (MMU) • Swap disk/file • Logical address • Physical address
Fragmentation • Internal fragmentation
Fragmentation • Internal fragmentation • External fragmentation