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

Software engineering, assignment on transaction flow, transform flow, trans...

assignment on transaction flow, transform flow, transform mapping: refining the architectural design

Backpropagation learning routine, Backpropagation Learning Routine: Co...

Backpropagation Learning Routine: Conversely as with perceptrons there the information in the network is stored in the weights than the learning problem comes down to the ques

Explain can we have constant volatile variable, Const and volatile keywords...

Const and volatile keywords should not be used together due to both are opposite in nature. A variable is declared as "const" means its value is not able to be altered but if i

What is the role of a controller in an mvc application, The controller resp...

The controller responds to user interactions, with the application, by selecting the act method to implement and also selecting the view to render.

What are the principles of transport layer, Q. What are the principles of t...

Q. What are the principles of transport layer? Transport layer: This layer is the first end-to-end layer. Header of transport layer includes information which helps send the

Conversion of decimal number 82.67 to its binary equivalent, Conversion of ...

Conversion of Decimal number 82.67 to its Binary Equivalent Ans. Firstly see the integer part 82 and determine its binary equivalent  as The Binary equivalent is (101001

What are the risks involved in electronic payment systems, What are the ris...

What are the risks involved in Electronic Payment Systems?    From the customer's perspective: Dishonest merchants or financial service providers Stolen payment

What is a zombie, What is a zombie? When a program forks and the child ...

What is a zombie? When a program forks and the child finishes before the parent, the kernel still keeps some of its information about the child in case the parent might require

What are the different tones used in strowger telephony, What are the diffe...

What are the different tones used in strowger telephony? Explain with the help of waveforms and the timings. Dial Tone: it is used to indicate that the exchange is ready to r

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