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

Develop inventory management system and time-tabling systems, Problem: ...

Problem: Develop three sub-systems namely Staff Profiling System, Inventory Management System and Time-tabling systems. (a) Show about any three design patterns you have us

Search-based tools, The search-based tools initially identify the problem a...

The search-based tools initially identify the problem and after that appropriately give advice on how to correct it. AT Expert from Cray Research is one of the tools being used

Granularity-concept of parallel execution and concurrent , Granularity ...

Granularity Granularity refers to the quantity of computation done in parallel relative to the dimension of the entire program. In parallel computing, granularity is a qualitat

Explain register indirect addressing, Q. Explain Register Indirect Addressi...

Q. Explain Register Indirect Addressing? In this addressing technique the operand is data in memory pointed to by a register. Or we can say in other words that the operand fie

What is domain explain, Q. What is Domain explain? Domain can be an apa...

Q. What is Domain explain? Domain can be an apartment complex, a town or even a country. Sub-domains can correspond to organizations like expertsmind. United States comes under

Explain the virtual memory, What is virtual memory?  Virtual memory is ...

What is virtual memory?  Virtual memory is a technique that permits the execution of processes that may not be completely in memory. It is the separation of user logical memory

What is the basic approach of page replacement, What is the basic approach ...

What is the basic approach of page replacement?  If no frame is free is available, find one that is not currently being used and free it. A frame can be freed by writing its co

Illustrate about the problem statement, Illustrate about the Problem statem...

Illustrate about the Problem statement Problem statement would not be incomplete, inconsistent and ambiguous. Try to state the requirements precisely and point to point. Do no

Explain about mainframes computer, Q. Explain about Mainframes computer? ...

Q. Explain about Mainframes computer? Mainframes, capable of executing in excess of 53 MIPS, are high-performance, general- purpose computers supporting very large databases, r

binary division program for signed integer, The program division.c is avai...

The program division.c is available for download as part of this assignment. It is a binary division program which works for signed integers. It contains a function, div32, which d

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