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 about the arithmetic shift, Explain about the Arithmetic Shift ...

Explain about the Arithmetic Shift An arithmetic shift micro operation shifts the signed binary number to left or right. The effect of the arithmetic shift left operation is

Define about hyper-threading technology, Q. Define about Hyper-threading te...

Q. Define about Hyper-threading technology? Hyper-threading technology enables a single microprocessor to behave as two separate threaded processors to operating system and app

Determine the begin - end keywords, Determine the begin - end keywords ...

Determine the begin - end keywords Group several statements together. Cause the statements to be evaluated sequentially (one at a time) -> Any timing within sequential group

Explain cpu based exchange, Explain CPU based exchange. CPU Based Exch...

Explain CPU based exchange. CPU Based Exchange: All the control equipment is replaced with a single processor that must be quite powerful, in centralized control. This should

Explain instruction cycle and execution cycle, Q Explain Instruction cycle ...

Q Explain Instruction cycle and Execution cycle. and also explain Instruction Counter, Memory Address Register and Memory Buffer Register.

Convert statement into conjunctive normal form , Consider the following sta...

Consider the following statements about the types of fruit people like. If people like apples, then they do not like oranges. If people do not like apples, then they like orang

Differentiate between $display and $strobe, Differentiate between $display ...

Differentiate between $display and $strobe These commands have similar syntax, and display text on screen during simulation. $display and $strobe display once every time they a

Define formal language grammar, Define formal language grammar? A forma...

Define formal language grammar? A formal language grammar is a set of formation rules which describe that strings made by the alphabet of a formal language are syntactically va

What do you mean by mouse protocols, Q. What do you mean by Mouse Protocols...

Q. What do you mean by Mouse Protocols? Mouse protocol is the digital code to that signal from the mouse gets converted. There are four main protocols: Microsoft, Mouse Systems

Circles in the visualization, To sktech the circles in the visualization, y...

To sktech the circles in the visualization, you need to use the paramteric equation of a circle (x = r cos (Θ), y = r sin(Θ). A circle can be shown as a polygon where the points of

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