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lecture10 - Memory Management Physical Memory After...

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Memory Management Physical Memory After considering the CPU for the last fewweeks, we’re ready to look at a newresource: memory .A hardware memory is a linear array of words. You can think of it as a function mapping an address to a value. Memories vary by the size of address space, that is the number of words theystore, and their addressing granularity, or the size of the words theyreturn. Most modern memories are byte (8-bit word) addressable. Multiple hardware memories are used to provide a larger address space. Frequently other hardware is multiplexedtothe address space: OS ROM I/O 0x0000 0xffff This is called memory mapping. In a memory-mapped I/O system, preventing a process from accessing devices directly is equivalent to preventing the process from accessing certain ranges of physical memory. Physical memory refers to storage provided by real devices. We’ll see other kinds.
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lecture10 - Memory Management Physical Memory After...

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