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

Difference between non-relocatable self relocatable programs, Differentiate...

Differentiate between non-relocatable self relocatable programs. A non-relocatable program is one which cannot be executed in any memory area other than the area starting at

Universal serial bus - computer architecture, Universal Serial Bus - comput...

Universal Serial Bus - computer architecture: USB   Universal Serial Bus   Speed Low-speed(1.5 Mb/s) High-speed(480 Mb/s) Full-speed(12 Mb/s)   De

Computer aided manufacture, Before we take a detailed look about software l...

Before we take a detailed look about software languages, let us consider the role of computers in engineering. Computers are commonly used in the areas of 'Computer Aided Design /

Demonstration of sorting problem, Q. Demonstration of sorting problem? ...

Q. Demonstration of sorting problem? The term sorting implies organising elements of a provided set of elements in a specific order i.e. descending order / ascending order / al

Physics, #questionabut diffraction ..

#questionabut diffraction ..

Scope of supply chain management consultancy, What are included in scope of...

What are included in scope of Supply Chain Management Consultancy? Supply Chain Management Consultancy's scope is extensive, and classically includes as given here: a. Sales

Application using shift operations, Application Using Shift Operations ...

Application Using Shift Operations Rotate and Shift instructions are helpful even for division andmultiplication. These operations are not normally available in high-level lang

Performance analysis, In order to calculate the performance of the program,...

In order to calculate the performance of the program, the normal form of analysis of the program is to simply measure the total amount of CPU time needed to implement the various p

Test, what persistance shouold i use

what persistance shouold i use

How many bits of data will be produced if voice is converted, If voice is c...

If voice is converted to digital form using PCM, how many bits of data will be produced in half a second? While voice is converted to digital by using PCM that is Pulse Code Mo

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