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(July 2012)| A memory management unit (MMU), sometimes called
paged memory management unit (PMMU), is a computer hardware
component responsible for handling accesses to memory requested
by the CPU. Its functions include translation of virtual
addresses to physical addresses (i.e., virtual memory
management), memory protection, cache control, bus arbitration
and in simpler computer architectures (especially 8-bit systems)
bank switching. Modern MMUs typically divide the virtual address
space (the range of addresses used by the processor) into pages,
each having a size which is a power of 2, usually a few
kilobytes, but they may be much larger. The bottom n bits of the
address (the offset within a page) are left unchanged. The upper
address bits are the (virtual) page number. The MMU normally
translates virtual page numbers t