CrazyEngineers Archive
Old, but evergreen and popular discussions on CrazyEngineers, presented to you in read-only mode.
@Mahesh • 09 Oct, 2006
What is difference between logical and physical address?
@xheavenlyx • 09 Oct, 2006 Ill take a shot:

Logical addrs: Its the address which we can see work on in calculations or programs at runtime. Eg, a pointer pointing to memorie.

Physical addrs: Its the actual addrss of the byte in hardware (ed, ram/rom) which is mapped by the logical addrss. After every compilation/execution the logical add can change but the physical will never.

Is it right is it right is it right?
@Mahesh • 10 Oct, 2006 Xh,you are correct but I want to know about how logical address is calculated and to what value it is added to get physical address.
@xheavenlyx • 10 Oct, 2006
Xh,you are correct but I want to know about how logical address is calculated and to what value it is added to get physical address.
You append a zero at the end of a logical addrs to get the physical addrs. Thats what is dont in a pentium type processor. Dont know about the AMD or others.
@Mahesh • 10 Oct, 2006 I don't think that by keeping 0 at last in logical address we get physical address.It varies from one process to other.Its value is added to base rregister address to get physical address.
@xheavenlyx • 10 Oct, 2006 No, this one I dont know😀

Give the answer in detail if you do. I really want to know.

@Mahesh • 10 Oct, 2006 I think you have this addressing in M.P. There we have this type addressing in 8086 .But this differs with addressing in our Computer Organisation.In this,
CPU generates logical address and physical address is found by adding with this with the value in a special register called relocation register.
@aashima • 10 Oct, 2006 Well physical address what i can recall is a part of the effective address. It is the actual path of the location of the particular data in the memory or elsewhere. Is it right?
@Mahesh • 11 Oct, 2006 Yes, you are correct.But I'm want to know more about logical address.
@sandhya23 • 12 Nov, 2008 The address generated by CPU is referred to as a logical address.
The address seen by the memory unit ,i.e,the one loaded into the memory address refister of the memory is referred to as physical address
@sauravgoswami • 12 Nov, 2008 After following ur discussion i came to know logical adder is adder generated by assembly language were as physical adder are those performed with digital gates and components...
@manupep • 18 Nov, 2008 Logical address and physical address comesin many situations (not only memory ,paging ..etc)

As a general talk we can say that physical address is the actual address of device, memory unit or whatever it is

Logical address is the address used by us for the better understandability of ourselves . Actual physical address format is difficult to handle (because of complex format) in our communicatin purposes . So we use logical address and mapping this logical add to physcical address.

If the doubt is still persist i will give one eg:

Everyone is aware of IP address . It is the address used to identify one machine in a network. (actually it is the address of the network card in that machine). But the actual address of the card ( the burned address by the manufacture is MAC address it is 48 bit long) .But we use IP address instead of MAC for comm. This situation IP is the logical address.

The meaning of logical , and physcical addr is situation dependent
@Raviteja.g • 18 Nov, 2008 excellent manu :clap:
i got a clear idea about them now😎

Related Posts

@shaji.m · Apr 20, 2016

dear sir, please help to get IS875 part3- 2015 version code.

@Shrikant Bedekar · Jan 23, 2014

The term Pressure Groups was coined in U.S. Pressure groups work to promote and defend their interests. They are not interested in capturing political power or contesting elections. Their aim...

@indianapple · Mar 16, 2010

Hello everyone, I'm in my final year of B.Tech. CS now. I have been placed in TCS as of now and I also have a GATE score of 464 this...

@sunit.soni · Nov 21, 2009

I need notes for computer graphics( 5th semester I.T). would anybody provide me ??? then please.

@suyash · Jun 24, 2007

[FONT="]TATVA’07: A RETROSPECTIVE[/FONT] [FONT="]The Annual Technical Festival of the Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology, Nagpur, had a successful inaugural edition which was organized from...