Embedded systems often use multiple memory devices. It is usually necessary to have a method
to organize these devices and protect the system from applications trying to make inappropriate
accesses to hardware. This is achieved with the assistance of memory management hardware.
ARM cores have three different types of memory management hardware—
o no extensions providing no protection
o a memory protection unit (MPU) providing limited protection
o a memory management unit (MMU) providing full protection
Non protected memory is fixed and provides very little flexibility. It is normally used for small,
simple embedded systems that require no protection from rogue applications
