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

Mapping, what is transform mapping and transaction mapping?

what is transform mapping and transaction mapping?

Write short note on associated vs. common channel signaling, Write short no...

Write short note on Associated vs. Common channel signaling. Associated vs Common channel signalling: The out band signalling suffers from the very restricted bandwidth.

Explain the different fields of an instructions, Explain the significance o...

Explain the significance of different fields of an instruction An instruction is a command given to a computer to perform a particular operation on some given data and the form

Last ant on rod, i want program code for the above question in c language

i want program code for the above question in c language

Explain branch instruction with control signals, Explain BRANCH instruction...

Explain BRANCH instruction with Control Signals. and explain SHIFT instruction with Control Signals.  Explain Register Transfer Language. What do you mean by Addressing Techn

Determine the current allocation state and granted process, An operating sy...

An operating system contains 3 resource classes. The number of resource units in these classes is 7, 7 and 10. The current resource allocation state is shown below:

Multi-operating systems, The assignment enhances the acquisition of new kno...

The assignment enhances the acquisition of new knowledge through reading, research and practical work in class and at home. It requires critical thinking applied to real life tasks

#title., REPRESENTATION OF POYNOMIAL OF 2 OR MORE VARIABLES USING ARRAY

REPRESENTATION OF POYNOMIAL OF 2 OR MORE VARIABLES USING ARRAY

Communications technology, COMMUNICATIONS TECHNOLOGY: The development ...

COMMUNICATIONS TECHNOLOGY: The development of communications technology is, in a sense, a symbol of man's effort to communicate rapidly over great distances. Communications te

What is ''preemption'' program, Program 'preemption' is? Ans. Forced de...

Program 'preemption' is? Ans. Forced de allocation of the CPU from a program that is executing on the CPU is called preemption program.

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