Main Memory

Main Memory

1. Background

   • memory
     • process
   • registers
     • CPU access directly
   • CPU clock
   • Cache
   • Binding Instructions
     • Compile time
       • absolute code
     • Load time
       • relocatable code
     • Execution time
     • physical address space
       • Logical address
         • virtual address
       • Physical address
     • Memory-Management Unit (MMU)
     • Dynamic Loading
     • Dynamic Linking
       • shared libraries

2. Swapping

   • Backing store
   • Roll out, roll in
   • ready queue

3. Contiguous Memory Allocation

   • interrupt vector
   • high memory
   • Relocation registers
     • smallest physical address
     • range of logical addresses
     • MMU
       • dynamically
   • Multiple-partition allocation
     • Hole
       • free partitions
     • allocated partitions
   • Dynamic Storage-Allocation Problem
     • First-fit
     • Best-fit
     • Worst-fit
   • Fragmentation
     • External Fragmentation
     • Internal Fragmentation
     • compaction

4. Paging

   • frames
   • pages
   • Address Translation Scheme
     • Page number
     • Page offset
   • Page Table
     • Page-table base register (PTBR)
     • Page-table length register (PRLR)
     • associative memory
     • translation look-aside buffers (TLBs)
     • address-space identifiers (ASIDs)
     • Associative Memory
     • Effective Access Time
       • Effective Access Time (EAT)
     • Memory Protection
       • Valid-invalid
     • Shared Pages
       • Shared code
       • Private code and data
     • Structure
       • Hierarchical
       • Hashed
       • Inverted

5. Segmentation

   • Architecture
     • Segment table
       • base
       • limit
     • Segment-table base register (STBR)
     • Segment-table length register (STLR)