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

Natural and artificial intelligence, Since the term artificial intelligen...

Since the term artificial intelligence was defined in the 1950s, experts have disagreed about the difference between natural and artificial intelligence. Can computers be pro

Sound and complete, Dictator Dim wants to replace counting, in particular, ...

Dictator Dim wants to replace counting, in particular, counting the population of his land. To keep an accurate population count, Dictator Dim has instructed his secretary to add o

Adding server-side include to the page, Step 1: Click on the icon in the ob...

Step 1: Click on the icon in the object tool bar Or Insert -> SSI Step 2: Select the file Step 3: Add the file Step 4: Provide the URL (where to be attached) Step

Interrupt signal interconnection network (isin), Interrupt Signal Interconn...

Interrupt Signal Interconnection Network (ISIN) When a processor needs to send an interruption to another processor, then this interrupt initial goes to ISIN, through which it

Estimate the circuit switched network, a) Total available bandwidth = 1 Mbp...

a) Total available bandwidth = 1 Mbps = 1000 Kbps Each user requires send data at the rate of = 500 kbps As it is circuit switched network we have to dedicate the bandwidth So the

Determine the primary memory of the server, Determine the primary memory of...

Determine the primary memory of the server The keys used for accessing the server are held at a secret location in the primary memory of the server. This area or location is hi

What are the types of operations required for instructions, What are the va...

What are the various types of operations required for instructions?  Data transfers among the main memory and the CPU registers Arithmetic and logic operation on data

What is machine language, What is Machine Language? To write program fo...

What is Machine Language? To write program for a computer we need to specify, directly or indirectly the sequence of machine instructions.  These instructions  inside  computer

What is the advantage of buffering, What is the advantage of buffering? Is ...

What is the advantage of buffering? Is buffering always effective? Justify your answer with help of an example. I/O buffer: One type of input-output requirement arises from d

Operating system, define request edge and assignment edge

define request edge and assignment edge

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