
MMU-004
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MMU Functional Description
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15.3 MMU Functional Description
The MMUs handle the translation from virtual into physical addresses. The requestor (either the camera
subsystem or the DSP mega cell or the EDMA module for IVA2.2) issues virtual addresses to the
respective MMU (MMU1 for the camera subsystem and MMU2 for the IVA2.2). The MMU translates these
virtual addresses into physical addresses to access the actual resource (memory) when the MMU instance
is enable. That is when MMUn.
[1] MMUENABLE is set to 1.
shows the relationship between the physical address, the virtual address, and the MMU.
Figure 15-4. MMU Address Translation
15.3.1 MMU Benefits
The MMU offers two major benefits:
•
Memory defragmentation: Fragmented physical memory can be translated into contiguous virtual
memory without moving data.
•
Memory protection: Illegal, that is, non-allowed accesses to memory locations can be detected and
prevented.
shows two typical MMU use cases.
2668
Memory Management Units
SWPU177N – December 2009 – Revised November 2010
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