Describe about address space and memory space, Computer Engineering

Assignment Help:

Q. Describe about Address Space and Memory Space?

An address used by a programmer will be termed as a virtual address and set of such addresses the address space. An address in main memory is known as a physical address. The set of these locations is termed as memory space. So address space is set of addresses produced by programs as they reference instructions and data, memory space comprises actual main memory locations directly addressable for processing.

Supposes a computer which has a main-memory capacity of 64K words (K=1024). 16-bits are required to specify a physical address in memory because 64K = 216. Assume that computer has auxiliary memory for storing information equivalent to capacity of 16 main memories. Let's signify address space by N and memory space by M we then have for this illustration: N = 16 × 64 K = 1024K and M = 64K.

In a multiprogramming computer system, data and programs are transferred to and from auxiliary memory and main memory based on demands obliged by CPU. Suppose program 1 is currently being executed in CPU. Program 1 and a part of its associated data are moved from secondary memory in the main memory as displayed in Figure below. Parts of programs and data require not being in contiguous locations in memory because information is being moved in and out and empty spaces may be available in scattered locations in memory.

1319_Describe about Address Space and Memory Space.png

Figure: Address and Memory Space in Virtual Memory

In our illustration address field of an instruction code will comprise 20 bits however physical memory addresses should be specified with just 16-bits. So CPU will reference data and instructions with a 20 bits address though information at this address should be taken from physical memory since access to auxiliary storage for particular words will be prohibitively long. A mapping table is then required as displayed in Figure below to map a virtual address of 20 bits to a physical address of 16 bits. Mapping is a dynamic operation that means every address is translated instantly as a word is referenced by CPU.  

323_Describe about Address Space and Memory Space1.png

Figure: Memory table for mapping a virtual table


Related Discussions:- Describe about address space and memory space

Temporary registers w and z, Why the temporary registers W and Z are named ...

Why the temporary registers W and Z are named so I mean we start from A,B,C,D,E then H and L coz H stands for higher bit nd L for lower bit of the address pointed by memory pointer

Balanced trees and their operations, what is ment by avl tree n insertion n...

what is ment by avl tree n insertion n deletion ,2-3 tress insertion n deletion

Differentiate between string constants & character constants, Computer Conc...

Computer Concepts & C Programming 1. Write a program to read four floating point numbers and find their sum and average. 2. What is the difference between string constants a

Explain web service - .net component, Can you give an example of when it wo...

Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component? Services which help in stock trading by giving analysi

Explain briefly the function of layers, Explain briefly the function of dif...

Explain briefly the function of different layers which are covered under end to end layer connectivity. Different layer are as follows: 1. Transport Layer:  This is res

In which network configuration all data/information pass, A distributed net...

A distributed network configuration in which all data/information pass through a central computer is (A)  Bus network                            (B) Star network (C)  Rin

Push and pop, i want flowchart for push, pop in stack element and display s...

i want flowchart for push, pop in stack element and display stack and exit

Concurrently read exclusively write, Q. Concurrently read exclusively write...

Q. Concurrently read exclusively write? It's one of the models based on PRAM. In this model, processors access the memory location simultaneously for reading whereas exclusivel

Write a subroutine in c for toggling the cursor, Write a subroutine in C fo...

Write a subroutine in C for toggling the cursor using old directives. ; ; use small memory model for C - near code segment _DATA SEGMENT WORD   'DATA'   CURVAL EQU   [B

Can math operations be performed on a void pointer, Can math operations be ...

Can math operations be performed on a void pointer? No. Pointer addition and subtraction are based on advancing the pointer by a number of elements. By explanation, if you have

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd