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 is the security vulnerabilities for vba, Microsoft Visual basic has it...

Microsoft Visual basic has its host of problems one such being macros, Macros can be formed which can make havoc for a programmer with good intentions. Also the security issue rest

Define nondeterministic tm, Define nondeterministic TM?  Arbitraril...

Define nondeterministic TM?  Arbitrarily chooses move when more than one possibility exists Accepts if there is at least one computation that terminates in an acceptin

How can we create an outline around text, Place some text wherever. Then cl...

Place some text wherever. Then click "Create path from text" in the "Text tool option" window. Then use "Edit" -> "Stroke path" and choose the appropriate options in the following

Push and pop, i want flowchart for push, pop in stack element and display s...

i want flowchart for push, pop in stack element and display stack and exit

Explain about synchronous dram, Q. Explain about Synchronous DRAM? One ...

Q. Explain about Synchronous DRAM? One of the most broadly used forms of DRAM is synchronous DRAM (SDRAM). Unlike the conventional DRAM that is asynchronous SDRAM exchanges dat

Visibility, hidden edge/surface removal

hidden edge/surface removal

Keys, why impotant keys

why impotant keys

Data rate limitations in PSTN's by using nyquist theorem, Explain with the ...

Explain with the help of Nyquist theorem, the data rate limitations in PSTN's. Data rates in PSTNs : A voice channel in a public switched telephone network is band restricted

Show the categories of web browser, Q. Show the categories of Web browser? ...

Q. Show the categories of Web browser? The two basic categories of Web browser are: • Text-only browsers: A text-only browser like Lynx allows you to view Web pag

Describe about data warehouse development life cycle, Data Warehousing 1....

Data Warehousing 1.  With necessary diagram, Describe about Data Warehouse Development Life Cycle. 2. Elucidate Metadata and what is its use in Data Warehouse Architecture?

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