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 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

C program, Write a program to find the area under the curve y = f(x) betwee...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

Explain about magnetic disk, Q. Explain about Magnetic Disk? A disk is ...

Q. Explain about Magnetic Disk? A disk is circular platter constructed of nonmagnetic material known as substrate, coated with a magnetisable material. This is used for storing

VLSI implementation of control unit, Q. VLSI Implementation of Control Unit...

Q. VLSI Implementation of Control Unit? A main potential advantage of RISC is VLSI implementation of microprocessor. VLSI Technology has decreased the delays of transfer of inf

How to modify or delete a custom class name, 1. Click Tools > General Optio...

1. Click Tools > General Options, and then click the Object Mapping tab. 2. From the Object type list, select the standard object type that is associated with the object class

The height of the left sub tree and height of the right tree, The differenc...

The difference among the height of the left sub tree and height of the right tree, for each node, is almost one.  AVL - tree

Truth tables - artificial intelligence, Truth Tables - artificial intellige...

Truth Tables - artificial intelligence: In propositional logic, where we are limited to expressing sentences where propositions are true or false - we can check whether a speci

What is uml, ? UML is called as Unified Modeling Language. ? it is used...

? UML is called as Unified Modeling Language. ? it is used to Graphical language for visualizing artifacts of the system. ? It Allow to make a blue print of all the aspects

Real-time systems, This document is intended to help students get started w...

This document is intended to help students get started with the real-time systems (RTS) assignment. We will start on the assignment together in the laboratory. Students will then c

What are the different pascal standards, The original Pascal standard was a...

The original Pascal standard was an unofficial standard documented by the author, Nicklaus Wirth, in "The Report". The first official standard was ISO 7185 issued in 1983. This was

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