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

Explain about different types of mice, Q. Explain about different types of ...

Q. Explain about different types of Mice? Mice can be classified on the foundation of numbers of buttons, position sensing technology or type of Interface:  Sensing Technol

What is cmp instruction, What is CMP instruction Comparison instruction...

What is CMP instruction Comparison instruction (CMP) is a subtraction that changes only the flag bits; destination operand never changes. A comparison is useful for checking th

Determine waiting and average waiting time of CPU, CPU burst time indicates...

CPU burst time indicates the time, the process needs the CPU. The following are the set of processes with their respective CPU burst time     (in milliseconds). Process

Explain progressive control, Explain the term Progressive Control. Pro...

Explain the term Progressive Control. Progressive Control: Step by step system is an illustration of progressive control. The connection is established in stages, in respo

What are the values of the slack or surplus variables, Consider the followi...

Consider the following linear programming problem: Minimize:        70M + 40N Subject to:           3M + 7N ≥ 233                             10M + 2N ≥ 254

Define object oriented and structured development, How object oriented deve...

How object oriented development is dissimilar from structured development object oriented development is dissimilar from structured development of the system. In the structure

General considerations for research -artificial intelligence, General Consi...

General Considerations for Research -artificial intelligence: If we can specify the initial state, the operators or a consumer and the goal check for a search problem, that al

Explain the concept of top-down design for a program, Explain the concept o...

Explain the concept of top-down design for a program. Top down Design: A top-down approach is fundamentally breaking down a system to gain insight into its compositional s

Approach to reasoning - first-order logic, Approach to reasoning - first-or...

Approach to reasoning - first-order logic: The formal approach to reasoning has bigger return and disadvantages. In generally we notice, if a computer program has proved somet

Knowledge representation - artificial intelligence, Knowledge Representatio...

Knowledge Representation: To recap, we now have some characterizations of "AI", that when an "AI" problem arises, you will be able to put all into context exactly, find the co

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