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 one modulation technique used for high speed modems, Explain at lea...

Explain at least one modulation technique used for high speed modems. FSK - Frequency Shift Keying: In such technique the frequency of the carrier signal is changed as per to

Truth tables, Any function can be expressed in a truth table.A truth table ...

Any function can be expressed in a truth table.A truth table lists all possible combinations ofinputs and gives the output produced in eachcase.Truth tables must include all combin

State the benefits of object oriented modelling, Benefits of object oriente...

Benefits of object oriented Modelling There are many benefits and advantages of object oriented modelling. Emphasis on quality and reuse are the major highlights of OOM. OOM p

Designing the instruction format, Q. Designing the instruction format is a ...

Q. Designing the instruction format is a complex art? Instruction Length Significance: It's the fundamental issue of the format design. It concludes the richness and flex

How the information should be retrieved from the database, In a report with...

In a report with an LDB attribute, you do not have to explain how the information should be retrieved from the database tables, but only how the data should be shown on the screen.

Define the role of organizationin computer architecture, Define the role of...

Define the role of organizationin computer architecture The organization is the set of resources that realizes the architecture which include the CPU, the memory and I/O contro

Types of buses, different types of buses with diagram

different types of buses with diagram

Simplify the expressions by using boolean postulates, Simplify the given ex...

Simplify the given expressions using Boolean postulates Y = (A + B)(A‾ + C)(B + C) Ans. Y = (A + B)(A‾ + C)(B + C) = (A A‾ + AC + B A‾ + BC) (B + C) = (AC + B A‾ + BC) (B + C)

C program, Write a program to find the area under the curve y = f(x) betwee...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

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