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

What is the working of sound cards, Q. What is the working of Sound cards? ...

Q. What is the working of Sound cards? Multimedia has become a very significant part of today's PC. Home user wants hear songs and watch movies. The Software developer hacking

Dynamic programming problem, KK manufacturing company is faced with demand ...

KK manufacturing company is faced with demand for its product in each of the next four periods as shown in Table 1.  It must decide upon a production schedule to meet these demands

What kinds of statements are present in an assembly language, What kinds of...

What kinds of statements are present in an assembly language program? Discuss. An assembly program contains subsequent three types of statements: 1. Imperative statements: The

Explain approaches to reuse free memory area in a heap, Discuss two main ap...

Discuss two main approaches to reuse free memory area in a heap. Two major approaches to reuse free memory area in a heap are: First-fit: Allocate the first hole which i

Define the concept of inheritance, Define the concept of Inheritance I...

Define the concept of Inheritance Inheritance is property of reusing the code within the object oriented development. While modelling, we look at the all the classes, and try

Technical Support Engineer, I''m seeking a challenging professional working...

I''m seeking a challenging professional working position in the field of Information Technology,where I’ll be given the chance to enhance & expand the skills & experience

One pointer variable be subtracted from another, Under what conditions can ...

Under what conditions can one pointer variable be subtracted from another? Pointer subtraction isn't used very much, but can be handy to determine the distances between two arr

Explain the virtual memory, What is virtual memory?  Virtual memory is ...

What is virtual memory?  Virtual memory is a technique that permits the execution of processes that may not be completely in memory. It is the separation of user logical memory

Algorithms, Data array A has data series from 1,000,000 to 1 with step size...

Data array A has data series from 1,000,000 to 1 with step size 1, which is in perfect decreasing order. Data array B has data series from 1 to 1,000,000, which is in random order.

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