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Hello fellas.

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Welcome back.

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In this lesson we shall give a very short overview of another extension often found close to the call.

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This is for memory management as we have described earlier embedded systems often use multiple memory

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devices and therefore is usually necessary to have a method to organize these devices and protect the

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system from applications trying to make improper access to the hardware.

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This can be achieved using some forms of memory management hardware cores have two different types of

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memory management hardware.

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The first is the known as the MP you the memory Protection Unit and the MP you provides a form of limited

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protection and the second is the IMU the memory management unit which provides a much more comprehensive

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protection.

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There is also the deferred option of not using memory protection hardware at all non protected memory

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is fixed and provides little flexibility and it is normally used for small and simple embedded systems

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that require no protection.

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MP You employs a rather simple system that uses limited number of memory regions.

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These regions as we shall see are controlled by a set of special registers in each of each region is

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defined with specific access permissions.

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MP is often used for systems that require memory protection by law but the systems do not have very

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complex memory maps.

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So with a system that has a simple memory map it requires the memory protection the MP you can simply

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be used to emulate the other hand like I just said is very comprehensive.

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The MMR you use is a set of translation tables to provide control over memory.

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These tables are stored in the main memory and provide a fake war to physical address map as well as

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access permissions we should talk a bit more about memory management when we write in code to demonstrate

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how they work.

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So this order is for memory management now and I'll see you in the next lesson.