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

RISC performance using optimizing compilers, Q. RISC Performance using opti...

Q. RISC Performance using optimizing compilers? Performance using optimizing compilers: As instructions are simple compilers can be developed for efficient code organization a

The information on the current screen, How do you find the information on t...

How do you find the information on the current screen? The information on the present screen can be found by SYSTEM ? STATUS command from any menu.

Artificial intelligence software, Artificial Intelligence Software A...

Artificial Intelligence Software Artificial Intelligence (AI) software employs non numerical algorithms to resolve complex problems that are not amenable to computation or s

State the basic properties of this analytical engine, State the basic prope...

State the basic properties of this analytical engine The basic properties of this analytical engine are: It was a common purpose programmable machine. It had provisi

Explain the term - strong typing and weak typing, Explain the term - Strong...

Explain the term - Strong Typing and  Weak Typing Strong Typing : When any operation upon an object can be checked during compile time, when type is confirmed forcefully.

Explain the programmable rom (prom) - computer memory, Explain the Programm...

Explain the Programmable ROM (PROM) - Computer Memory? This is a kind of ROM that can be programmed using special equipment it can be written to, but only once and this is usef

Explain bit slice ALUs, Bit Slice ALUs It was possible to manufacture ...

Bit Slice ALUs It was possible to manufacture smaller like 4 or 8 bits fixed point ALUs on a single IC chip. If these chips are constructed as expendable types then employing

Database management system, what is time out based schemes in concurrency c...

what is time out based schemes in concurrency control

Types of validation controls provided by asp.net, Types of validation contr...

Types of validation controls provided by ASP.Net There are following types of validation controls provided by ASP.Net: 1. Required Field Validator 2. Compare Validator

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