OS Physical and Logical Address Space

OS Physical and Logical Address Space with Definition and functions, OS Tutorial, Types of OS, Process Management Introduction, Attributes of a Process, Process Schedulers, CPU Scheduling, SJF Scheduling, FCFS with overhead, FCFS Scheduling etc.

<< Back to OS

next → ← prev

Physical and Logical Address Space

Physical Address Space

Physical address space in a system can be defined as the size of the main memory. It is really important to compare the process size with the physical address space. The process size must be less than the physical address space.

Physical Address Space = Size of the Main Memory 

If, physical address space = 64 KB = 2 ^ 6 KB = 2 ^ 6 X 2 ^ 10 Bytes = 2 ^ 16 bytes
 
Let us consider,
 word size = 8 Bytes = 2 ^ 3 Bytes 

Hence,
 Physical address space (in words) = (2 ^ 16) / (2 ^ 3) = 2 ^ 13 Words 

Therefore,
 Physical Address = 13 bits

In General, 

If, Physical Address Space = N Words 

then, Physical Address = log2 N

Logical Address Space

Logical address space can be defined as the size of the process. The size of the process should be less enough so that it can reside in the main memory.

Let's say,

Logical Address Space = 128 MB = (2 ^ 7 X 2 ^ 20) Bytes = 2 ^ 27 Bytes 

Word size = 4 Bytes = 2 ^ 2 Bytes 

Logical Address Space (in words) = (2 ^ 27) / (2 ^ 2) = 2 ^ 25 Words 

Logical Address = 25 Bits 

In general, 

If, logical address space = L words 

Then, Logical Address = Log2L bits

What is a Word?

The Word is the smallest unit of the memory. It is the collection of bytes. Every operating system defines different word sizes after analyzing the n-bit address that is inputted to the decoder and the 2 ^ n memory locations that are produced from the decoder.

Next TopicPage Table

← prev next →

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

Related Links

Adjectives Ado Ai Android Angular Antonyms Apache Articles Asp Autocad Automata Aws Azure Basic Binary Bitcoin Blockchain C Cassandra Change Coa Computer Control Cpp Create Creating C-Sharp Cyber Daa Data Dbms Deletion Devops Difference Discrete Es6 Ethical Examples Features Firebase Flutter Fs Git Go Hbase History Hive Hiveql How Html Idioms Insertion Installing Ios Java Joomla Js Kafka Kali Laravel Logical Machine Matlab Matrix Mongodb Mysql One Opencv Oracle Ordering Os Pandas Php Pig Pl Postgresql Powershell Prepositions Program Python React Ruby Scala Selecting Selenium Sentence Seo Sharepoint Software Spellings Spotting Spring Sql Sqlite Sqoop Svn Swift Synonyms Talend Testng Types Uml Unity Vbnet Verbal Webdriver What Wpf

TheDeveloperBlog.com