Logical Address vs. Physical Address

Difference Between Logical Address and Physical Address

In simple terms, an address generated by the processor is known as a logical address. Logical addresses are also mentioned as virtual addresses. From the point of view of a program which is in motion, an element seems to be located in the address provided by logical address. Physical address (called also real addresses) is address seen by the unit of memory and he allows achieving a cell particular memory in main memory by the bus of data.

What is a logical address?

Logical address is the address generated by the processor. From the point of view of a program which is in motion, an element seems to be located in the address provided by logical address. The programs of application which comply on the computer do not see physical addresses. They always work by using logical addresses. The space of located logic is all the logical addresses generated by a program. Logical addresses have to be mapped at physical addresses before they are used and this mapping is manipulated with the aid of a material peripheral called the Unit of management memo (MMU). It is schemata of shape used by MMU. In the simple schema of mapping, the value in the register relocation is added to every logical address produced by the programs of application before sending them to memory. Also some other complex methods which are used to generate the mapping are there. Address constraining (i.e. instructions given in attribution and at addresses memory) can occur in three different epochs. Constraining address which can arrive in the time of compilation, if the real sites of memory are beforehand known and it would be to generate code absolute in compilation. Constraining address can also occur at the time of the load, if the sites of memory are not beforehand known. For it, re-localizable encode must be generated at the time of compilation. Moreover the fixing of address which can arrive at the time of execution can also be done. It requires a material support for the mapping of address. To compile and of constraining address at the time of load, logical and physical addresses are the same. But by linking address execution at the run time, they differ.

What is physical address?

Physical address or true address is address seen by the unit of memory and it allows the bus of data to achieve a cell of particular memory in main memory. Logical addresses generated by CPU during the execution of a program are cartographies by using at the physical address of MMU. For instance, by using the simple schema of mapping, who adds relocation register (let us assume that the value in the register is y) of the value at logical address, a beach of logical addresses of 0 in x would be a card for there beach of physical addresses in x there. This is also called the space of physical address of this program. All logical addresses have to be mapped at physical addresses in before they cannot be used.

What is difference between a logical address and a physical address?

Logical address is the address generated by the processor (in the perspective of a program which carries out), while physical address (or real address) is address seen by the unit of memory and it allows the bus of data to achieve a cell of particular memo in main memory. All logical addresses have to be mapped at physical addresses and in before they cannot be used by MMU. Physical and logical addresses are the same during the use of compilation and compelling address of load of time, but they differ when you use address at the time of execution constraining.

 

 

 

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