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

State the term- $display and $write, State the term- $display and $write ...

State the term- $display and $write $display and $write two are the same except which $display always prints a newline character at the end of its execution.

Secret-key encryption, Secret-key encryption is also called as Private ...

Secret-key encryption is also called as Private encryption.

Overflow condition in linked list, Overflow condition in linked list may ha...

Overflow condition in linked list may happen when attempting to Make a node when free space pool is empty.

Final implementation of object oriented modelling, Final Implementation of ...

Final Implementation of Object oriented modelling Final Implementation: At this phase, the final execution of classes and  relationships developed while object design takes

Explain the uses of arithmetic processor, Explain the uses of arithmetic pr...

Explain the uses of arithmetic processor A processor has arithmetic processor (as a sub part of it) which executes arithmetic operations.  The data  type,  assumed  to  reside

Breakthrough for computer engineering, what is the importance of chemistry ...

what is the importance of chemistry for computer engineering?

What is the main problem with segmentation, What is the main problem with s...

What is the main problem with segmentation? Problem with segmentation (i) Is with paging, such mapping needs two memory references per logical address that slows down the

What is memory interleaving, Q. What is Memory Interleaving? In this sc...

Q. What is Memory Interleaving? In this scheme main memory is splitted in 'n' equal-size modules and CPU has separate Memory Base register and Memory Address Register for every

How future environment changes can be predicted - simulation, How future cl...

How future climate/environment changes can be predicted -  Information over time is fed into a weather/climate model -  based on changes in weather patterns, carries out a s

Quantity amounts (data type quan), A field containing quantity amounts (dat...

A field containing quantity amounts (data type QUAN) must be assigned to a reference table and a reference field. Explain? As a reference table, a system table having all the v

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