Memory Management Unit

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What Does Memory Management Unit Mean?

A computer’s memory management unit (MMU) is the physical hardware that handles its virtual memory and caching operations. The MMU is usually located within the computer’s central processing unit (CPU), but sometimes operates in a separate integrated chip (IC). All data request inputs are sent to the MMU, which in turn determines whether the data needs to be retrieved from RAM or ROM storage.


A memory management unit is also known as a paged memory management unit.

Techopedia Explains Memory Management Unit

The memory management unit performs three major functions:

  • Hardware memory management
  • Operating system (OS) memory management
  • Application memory management

Hardware memory management deals with a system’s RAM and cache memory, OS memory management regulates resources among objects and data structures, and application memory management allocates and optimizes memory among programs.

The MMU also includes a section of memory that holds a table that matches virtual addresses to physical addresses, called the translation lookaside buffer (TLB).


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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.