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

Give example of stack using encapsulation of OOA, Give example of stack usi...

Give example of stack using encapsulation of OOA An example of the Stack.  A Stack abstraction provides methods like pop (), push (), isEmpty(), isFull(). The Stack can be i

What does a socket having of, The combination of an IP address and a port n...

The combination of an IP address and a port number is known as a socket.

What is structured programming, What is structured programming? Structu...

What is structured programming? Structured Programming: means the collection of principles and practices that are directed toward developing right programs which are simple to

Explain the term instruction cycle, Instruction Cycle The instruction c...

Instruction Cycle The instruction cycle consists of a series of steps required for the execution of an Instruction in a program. A distinctive instruction in a program is compo

Human–computer interaction, In the view of the M364 module team, HCI has be...

In the view of the M364 module team, HCI has been superseded by ID. This is because HCI traditionally concentrated upon desktop computers with single users, whereas ID includes the

What is drop-down list, A dialog box such as a File menu that have one comm...

A dialog box such as a File menu that have one command until it is clicked when a number of dissimilar commands "drop-down."

Explain the categories of design patterns, Question: (a) Explain the th...

Question: (a) Explain the three categories of design patterns. Give two examples from each category. (b) When describing a pattern what is the purpose of "The Intent", an

Determine the order in which optimized c-scan would service, Consider the s...

Consider the situation in which the disk read/write head is currently located at track 45 (of tracks 0-255) and moving in the positive direction. Assume that the following track re

Explain 16-bit ROM array, Draw the logic diagram of 16-bit ROM Array and ex...

Draw the logic diagram of 16-bit ROM Array and explain its principle of operation. Ans: 16-bit ROM Array: A ROM that is read-only memory is an array of selectively closed

Explain gray code, Explain Gray Code Ans. Gray Code 1.  Extreme...

Explain Gray Code Ans. Gray Code 1.  Extremely useful code. Also termed as reflected code. 2.  All gray code is different from the preceding and succeeding codes thr

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