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

Electronic brokerage facilitate search and retrieval, How does electronic b...

How does electronic brokerage facilitate search and retrieval of information? E Brokerage facilitates search and retrieval of Information: The success aspect of a brokera

Explain essential properties of distributed operating system, Describe the ...

Describe the essential properties of the Distributed Operating System Essential properties of Distributed operating systems: Sharing resources Calculation speed-up

Rpn procedure, Apply this algorithm to your MASM program 1) Declare the ...

Apply this algorithm to your MASM program 1) Declare the following variables in your data segment: .data ; ; These are the values of the variables ; Variables

How to call a wml script from a wml page, WML & WML Script 1. How to ca...

WML & WML Script 1. How to call a WML Script from a WML Page? 2. Write a brief note on WML Script Operators and Expressions. 3. Write brief notes on WML Script Statements

Call a screen as dialog box, The Syntex used to call a screen as dialog box...

The Syntex used to call a screen as dialog box (pop up)is CALL SCREEN STARTING AT ENDING AT

Minimum possibility -minimax algorithm, Minimum possibility -minimax algori...

Minimum possibility -minimax algorithm: Finally, we want to put the scores on the top edges in the tree. So there is over again a choice. Whenever, in this case, we have to r

Determine the operations from functions, Operations from Functions As ...

Operations from Functions As we know, function is actually operations on object. These   functions could be simple and summarized on object model. Organise functions into oper

What is called when distortion caused on telephone line, Distortion caused ...

Distortion caused on telephone line by an adjacent one is called (A) Cross Fire                      (B) Inductive Disturbance (C)  Cross Talk                     (D) Non

What is random access memory, What is random access memory(RAM or MAIN MEMO...

What is random access memory(RAM or MAIN MEMORY) and mention its types? The main memory in the central storage unit in a computer system. It is relatively large and fast memory

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