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

Subtraction of 01100-00011 using 2's complement method, Subtraction of 0110...

Subtraction of 01100-00011 using 2's complement method Ans. Firstly 1's complement of 00011 is 11100 and 2's complement is 11100 + 1 = 11101. Thus If a last carry is

Explain various classes of datatypes of c, Explain various classes of datat...

Explain various classes of datatypes of C   Following are the main classes of data types in C language: 1.  Primary data types: Also called as fundamental/basic data types

Show how pages will be allocated using first-in-first-out, Consider the fol...

Consider the following page reference and reference time strings for a program: Page reference string: 5,4,3,2,1,4,3,5,4,3,2,1,5,..... Show how pages will be allocated using t

Postpurchase interaction, Postpurchase Interaction Customer service an...

Postpurchase Interaction Customer service and support: The considerations at this stage can be explained by the following example: Consider a bundle having of a portfolio

System analysis and design, write an algorithm on railway reservation ticke...

write an algorithm on railway reservation ticket window

Kruskal''s, Image Segmentation with Minimum Spanning Forests (50 points). D...

Image Segmentation with Minimum Spanning Forests (50 points). Develop a Python 3 implementation of the image segmentation algorithm that we explored on the first day of class. Your

Components of information super highway infrastructure, Explain the compone...

Explain the components of Information Super Highway Infrastructure. The Information Superhighway is more than the Internet. It is a sequence of components, having the collectio

Illustrate the term extranet, Illustrate the term Extranet? Extranet:...

Illustrate the term Extranet? Extranet: Extranet is Extension of an Intranet that makes thelatter accessible to outside companies or individuals with or without an intran

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