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

Differentiate the latch and flip-flop, Differentiate the latch and flip-flo...

Differentiate the latch and flip-flop? The major difference between latch and FF is which latches is level sensitive whereas FF is edge sensitive. They both need the use of clo

Give brief explanation about the keyboards, Give brief explanation about th...

Give brief explanation about the keyboards Keyboards are generally not offered as the number of options is limited and owners of the system do not want customers keying in info

Explain about annotational notations, Explain about Annotational Notations ...

Explain about Annotational Notations These notations may be applied to describe remark and illuminate about any element in the model. They are considered as explanatory of U

For which class address 192.5.48.3 belogs, Address 192.5.48.3 belongs to? ...

Address 192.5.48.3 belongs to? Address 192.5.48.3 belongs to class C.

Ruby, Discuss about variables and assignmesnt statements

Discuss about variables and assignmesnt statements

Find the generating function, Find the generating function to denote the nu...

Find the generating function to denote the number of ways the sum 9 can be acquired while 2 distinguishable fair dice are tossed and the first shows an even number and the second s

What is a convertor?, Converter is an application that converts distance me...

Converter is an application that converts distance measurements among metric and U.S units.

Level of any node of a tree, Level of any node of a tree is :- Its distanc...

Level of any node of a tree is :- Its distance from the root

Explain the term- intranet, Explain the term- Intranets Various compani...

Explain the term- Intranets Various companies use intranets as well as the internet. Simple definition is "An intranet is a computer network which is based on internet technolo

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