Hello fellas.
Welcome back.
In this lesson we shall give a very short overview of another extension often found close to the call.
This is for memory management as we have described earlier embedded systems often use multiple memory
devices and therefore is usually necessary to have a method to organize these devices and protect the
system from applications trying to make improper access to the hardware.
This can be achieved using some forms of memory management hardware cores have two different types of
memory management hardware.
The first is the known as the MP you the memory Protection Unit and the MP you provides a form of limited
protection and the second is the IMU the memory management unit which provides a much more comprehensive
protection.
There is also the deferred option of not using memory protection hardware at all non protected memory
is fixed and provides little flexibility and it is normally used for small and simple embedded systems
that require no protection.
MP You employs a rather simple system that uses limited number of memory regions.
These regions as we shall see are controlled by a set of special registers in each of each region is
defined with specific access permissions.
MP is often used for systems that require memory protection by law but the systems do not have very
complex memory maps.
So with a system that has a simple memory map it requires the memory protection the MP you can simply
be used to emulate the other hand like I just said is very comprehensive.
The MMR you use is a set of translation tables to provide control over memory.
These tables are stored in the main memory and provide a fake war to physical address map as well as
access permissions we should talk a bit more about memory management when we write in code to demonstrate
how they work.
So this order is for memory management now and I'll see you in the next lesson.