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

How a typical dma controller can be interfaced to an 8086, Demonstrate how ...

Demonstrate how a typical DMA controller can be interfaced to an 8086/8085 based maximum mode system.  For 8088 in maximum mode: The RQ/GT0 and RQ/GT1 pins are used to is

Analog-to-digital conversion process, A stationary random displacement sign...

A stationary random displacement signal was digitised at 64 samples a second and analysed to obtain an auto-spectral density.  The signal was calibrated in mm units.  The frame siz

Estimate the size of the state space, 1. The missionaries and cannibals pro...

1. The missionaries and cannibals problem. Three missionaries and three cannibals are on the left river bank, with a boat that can hold one or two people. If on either side of the

C program, program to find minimum total number of shelfs

program to find minimum total number of shelfs

List the allowed register pairs of 8085, List the allowed register pairs of...

List the allowed register pairs of 8085. B-C register pair D-E register pair H-L register pair

Explain HLL program & execution of machine language program, Give the Schem...

Give the Schematic of Interpretation of HLL program and execution of a machine language program by the CPU. The CPU utilizes a program counter (PC) to notice the address of nex

Chemistry, application problems on electrochemical series

application problems on electrochemical series

General registers in a processor, In this segment, we will give very brief ...

In this segment, we will give very brief details of registers of a RISC system known as MIPS. MIPS is a register-to-register or load/store architecture and employs three address

Assembly language programes, Program to calculate the value of the series 1...

Program to calculate the value of the series 1+x+x2+x3+.... +xn. Read the values of ''x'' and ''n'' from the keyboard.

Classes of experts system, 1. The Consultant : A consultant is an experts...

1. The Consultant : A consultant is an experts person who possesses a high level of expertise in the area. He guide and educate the executives regarding establishing the e

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