.::Virtual Memory::.

  • Each process is given its own 32-bit address space.
  • Paging is used to remap an virtual address within one program to different physical addresses in memory. The Pentium uses a page frame size of 4,096 bytes, which is physical memory, and has 2^20 different pages in virtual memory space.
  • OS keeps track of pages to page-frames.
  • Page table is used to translate the H.O. bits of a virtual address to select a page. The L.O. bits of the virtual address are used as an index into the page. Mapping between virtual and physical addresses is given below.
  • Page Table Entries
  • To prevent cluttering the data cache with page table entries the page table uses its own cache know as the TLB. This cache usually has 32 entries on a Pentium processor.