The process of converting a logical address into a physical memory address is called "relocation". The logical address issued by the program is not the actual storage location of the data or instructions, but this address can be converted to obtain the physical address of the actual storage location, which is equivalent to a relocation.
The operating environment of this tutorial: Windows 7 system, Dell G3 computer.
The process of converting a logical address into a physical address in memory is called "relocation".
The address of the content generated by the central processing unit when the program is running is called a logical address. This address is also called a virtual address. When we talk about logical addresses, we are referring to the addresses that the CPU assigns to each process. The actual address a process is in memory is different from the address the process thinks it is at.
Whenever the CPU runs a process, it allocates a specific memory to that process. This allocated memory space is located at the logical address that the CPU generates for the process.
When generating a logical address, the CPU generates an address, and the program adds the base address to the address generated by the CPU to obtain the
逻辑地址 = 基地址 + CPU 生成地址
The physical address is where the process and its contents are placed in main memory or hard disk. The address is the actual address of the memory unit in the memory. This address cannot be accessed or viewed directly by the user program, so the logical address needs to be mapped to this address so that it can be accessed with the help of a pointer that shows the location rather than the code
And the logical address issued by the program is not for data or instructions The real storage location, but this address can be converted to obtain the physical address of the real storage location, which is equivalent to a relocation.
(MMU is a memory management unit)
Simple understanding:
The logical address is a relative address, such as 1G Allocate 1M space in the memory. The first byte in this 1M space is even the logical address
. Starting from 100M of 1G memory, 1M space is allocated. At this time, the first byte of 101M, This refers to the physical address.
Another example: There are four people who want to rent a house. The address of the house is No. XX, XX Street. This address is the actual address, which is the physical address. The landlord numbered these four houses 1 2 3 4. These four people usually talk about which room they live in. This is the logical address, but the actual address is still No. XX, XX Street.
Difference:
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