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 is connection, An established communication session among a server and...

An established communication session among a server and a workstation.

Define parity generator, Define parity generator During transmission, a...

Define parity generator During transmission, at sending end the message is applied to a parity generator, where the needed bit is formed.

How does computer know that overflow has happened, Q. How does computer kno...

Q. How does computer know that overflow has happened? Illustration: Add numbers 65 and 75 in 8 bit register in signed 2's complement notation.  Here expected result is

What is analysis iteration, Analysis Iteration   To understand any prob...

Analysis Iteration   To understand any problem completely you have to repeat task which implies that analysis requires repetition. First, just get overview of problem, make a r

Define functions with that virtual memory can be implemented, Virtual memor...

Virtual memory can be implemented with ? With Segmentation and Paging Virtual memory can be implemented.

Transfer data among computers on the internet, Tool that is used to transfe...

Tool that is used to transfer data/files among computers on the Internet TCP (Transfer control protocol)

Commutatively of connectives - artificial intelligence, Commutatively of Co...

Commutatively of Connectives You will be aware from the fact that some arithmetic operators have a property that it does not matter which way around you give the operator input

Disadvantages of asynchronous and synchronous reset, What are disadvantages...

What are disadvantages of the asynchronous reset and synchronous reset? Disadvantages of asynchronous reset: Make sure that the release of the reset can arise within one c

A universal shift register can shift in both the lef, #question.A universal...

#question.A universal shift register can shift in both the left-to-right and right-to-left directions, and it has parallel-load capability. Draw a circuit for such a shift register

Explain error-detection code, Q. (192.8)10 - (AE.E)16 = (X)8, Find value of...

Q. (192.8)10 - (AE.E)16 = (X)8, Find value of x. Use 8's complement method. Q. Write first 10 numbers in the base 4. Q. Explain Error-Detection code & Error-correction code w

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