Bit manipulation techniques, Computer Engineering

Assignment Help:

  We can also use the logical operators to numbers directly and  perform simple bit manipulation . The operators are

    &  Bitwise AND
    |  Bitwise OR
    ^  Bitwise exclusive or 
    ~  Bitwise one's complement i.e. NOT
    <<  Left shift
    >>   Right shift

Example
  A 8 bit number represents a coded function, bit  3-4 describes the operation to be performed on the number in bits 0- 2 and 5-7  the function i.e. 
 
    00    Add
    01    Subtract
    10     Divide
    11    Multiply
 
  Write a Program to extract the number and operation

Answer
We need to extract the bits 3-4, the answer is bit operators 
 
    Assume number is in the variable A i.e.  11011011
 
    Mask off the first number i.e. bit 0-2
    num1 = a & 0x07;        11011011 and
                00000111
                00000011
    
    Mask off the second number i.e. bit 5 -7
    num2 = a & 0xe0;        11011011 and
                11100000
                11000000
 
    We need to shift num2 down by 5 places i.e.
    num2 = num2 >>5;
                00000110

This could be done in one instruction i.e.
    num2 = (a & 0xe0) >> 5;
 
  Mask off the operation bits i.e. bit 4-5
    operation = (a & 0x18) >> 3;
 
  We can then use the switch statement to select each operation
  switch(operation)
  {
  case 0:  
    total = num1+num2;
    break;
  case 1: 
     total = num1-num2;
    break;
  case 2:  
    total = num1/num2;
    break;
  case 3:  
    total = num1*num2;
    break;
  }
Hence the entire program is 
  #include
  void main()
  { 
  char prompt;
  /*Author : Mr James Mc Carren 
  Company: Staffordshire University 
   Date: 26th August 2012 
  Version 1.0 
   Function : To show bit manipulation
   Modifications:   none*/
  int num1,num2,operation,total,a;
  printf("Please enter in the number\n\r");
  scanf("%x",&a);
  num1 = a & 0x07;  
  num2 = (a & 0xe0) >> 5 ;
  operation = (a & 0x18) >> 3;
  switch(operation)
  {
  case 0:   total = num1+num2;
    break;
  case 1:  total = num1-num2;
    break;
  case 2:  total = num1/num2;
    break;
  case 3:  total = num1*num2;
    break;
  }
  printf("The total is %d\n\r",total); 
  printf("Press and key to exit \n\r");
  scanf("\n%c",&prompt);
  }


Related Discussions:- Bit manipulation techniques

Show the connection between different networks, Q. Show the Connection betw...

Q. Show the Connection between different networks? The connection between different stages is made in following manner:  all outputs of 1 st crossbar switch of first stage a

Define a formal system, Q. Define a Formal System? A Formal System is o...

Q. Define a Formal System? A Formal System is one which is planned in advance and is used according to schedule. In this system procedures and policies are documented well in a

What is a work process, What is a work process? A work process is where ...

What is a work process? A work process is where individual dialog steps are in fact processed and the work is done.  Every work process ocuurs one type of request.

Or-introduction rule, Or-Introduction : Thus if we know about one thin...

Or-Introduction : Thus if we know about one thing is true, and also we know that a sentence when there thing is in a disjunction is true. Here if we consider example, like we

Introduction to the operating system, Q. Introduction to the Operating Syst...

Q. Introduction to the Operating System? An Operating system is software that creates a relation between the User, Hardware and Software. It is an interface between the all.

How does cpu know that an interrupt has taken place, How does CPU know that...

How does CPU know that an interrupt has taken place? There needs to be a line or a register or status word in CPU which can be increased on occurrence of interrupt situation.

What technology used by magento, Magento uses PHP as a web server scripting...

Magento uses PHP as a web server scripting language and the MySQL Database. The data model is based on the Entity-attribute-value model that stores data objects in tree structures,

what respects the advance builds, Describe your choice specifically and fu...

Describe your choice specifically and fully, explaining and discussing at length in what respects the advance builds upon or departs from present technology or practice and the sev

Architecture, write a program in assembly language using emu8086 so that th...

write a program in assembly language using emu8086 so that the input string can contain both lower and upper case letters and any other character and the output will be the reverse

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