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 main functions of sound cards, Q. What are the main functions ...

Q. What are the main functions of sound cards? Sound card (The card is frequently directly built into motherboards these days) is a board that has digital to analog sound conve

Define bootstrap loader, Define bootstrap loader? The ROM portion of ma...

Define bootstrap loader? The ROM portion of main memory is required for storing an initial program known as bootstrap loader. It is a program whose function is to start the com

Shell scripting, Write a script called addnames that is to be called as fol...

Write a script called addnames that is to be called as follows, where classlist is the name of the classlist file, and username is a particular student''s username. ./addnames cla

What is internet routing hierarchy, Q. What is Internet Routing Hierarchy? ...

Q. What is Internet Routing Hierarchy? So how do packets find their way across Internet? Does every computer connected to Internet know where other computers are? Do packets ba

Define abap/4 layer, Define ABAP/4 layer? The ABAP/4 layer defines the ...

Define ABAP/4 layer? The ABAP/4 layer defines the data formats used by the ABAP/4 processor.

Explain about the term- reports, Explain about the term- Reports Repor...

Explain about the term- Reports Reports are produced as a result of questions like "how many times has a type of car broken down" or "which cities have the highest house price

Show sample instruction format of mips instruction, Q. Show Sample Instruct...

Q. Show Sample Instruction Format of MIPS instruction? Early MIPS architectures had 32-bit instructions and later versions have 64-bit implementations. The first commercial

Java Programming, How to parse n size depth node in java and create output ...

How to parse n size depth node in java and create output in same tree format?

What is instruction register, Q. What is Instruction Register? Instruct...

Q. What is Instruction Register? Instruction Register (IR): Here instructions are loaded before execution. Comments on figure above are as below: All representations are

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