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 are different adder circuits you studied, Half Adder (for addition of ...

Half Adder (for addition of two bits) Full Adder (for addition of three bits) Carry look ahead adder Carry save adder Carry propagate adder

Define colgroup tag, COLGROUP defines a group of columns in table and...

COLGROUP defines a group of columns in table and allows you to set properties of those columns. goes immediately after tag and before an

Software architecture of microprocessor, The 68HC11 series is based on the ...

The 68HC11 series is based on the Motorola 6800/1 programming instruction set and hence is a fairly simple 8 bit microprocessor. The internal structure of the 6800/1 is shown below

Memory organization - computer architecture, Memory Organization - Computer...

Memory Organization - Computer architecture: BASIC CONCEPTS: Address space - 16-bit : 216 = 64K mem. locations - 32-bit : 232 = 4G mem. locations -          40-b

Recursive binary search, The implementation of a (non-recursive) binary sea...

The implementation of a (non-recursive) binary search of an array. The assumption is that a given array is sorted. We want to see if a particular value, that we'll call the target

How to transmits data in the active message buffer, Q. How to Transmits dat...

Q. How to Transmits data in the active message buffer? int pvm_bcast( char *group, int msgtag ) Transmits data in the active message buffer to a group of processes. msgt

Console application with a class, Make a console application with a class '...

Make a console application with a class 'Account' having variables as id(int) and name (String).Add property 'account-no' which can be set andget. Add a 'ReadOnly' property 'IntRat

Cross bar-various interconnection networks-fully connected, Cross Bar ...

Cross Bar The crossbar network is the easiest interconnection network. It has a two dimensional grid of switches.  It is a non-blocking network and give connectivity among inp

What is divide overflow, What is divide overflow?  The division operati...

What is divide overflow?  The division operation might result in a quotient with an overflow. Overflow happens when the length of the registers is finite and will not hold a nu

Explain assembly program execution, Q. Explain Assembly program execution? ...

Q. Explain Assembly program execution? An assembly program is written according to a strict set of rules. A word processor or editor is used for keying an assembly program in t

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