Difference between revisions of "Memory management unit"
From ScienceZero
(New page: A memory management unit is is a layer of hardware between a CPU and memory. The virtual address space of a CPU is divided into pages and each page has an entry...) |
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Revision as of 21:42, 29 January 2007
A memory management unit is is a layer of hardware between a CPU and memory. The virtual address space of a CPU is divided into pages and each page has an entry in a table describing access rights and what physical memory address it maps to.
The page table is too large to fit in a CPU so the most recent entries are cached in the translation lookaside buffer. If a program is accessing memory in many different areas the TLB will not be able to fit all the needed entries and there is a large drop in performance as the CPU must load the page entry from memory for each memory access.
