Standard input- output using motorola and intel devices, C/C++ Programming

Assignment Help:

Talking to IO boards inside a computer or microcontroller depends upon the principles used by the microprocessor to address physical devices. On Motorola systems all devices connected to the processor local bus are memory mapped. Therefore it is fairly easier to address by means of a pointer the IO device, since it is just like RAM. In the case of Intel devices, the IO is not memory mapped, it is IO mapped. This causes a minor problem is accessing such devices, since the processor has to use IN, OUT commands and the address, therefore a simple pointer will not do. A non-ANSI function exists on PC's called 'portoutb' and 'portinb' these are used to input and output a byte of data (char) to an IO address (int). 

The syntax depends upon the compiler used by usually consists of
 
        outportb(address,data);
        data = inportb(address);
 
Care should be taken when porting code from an Intel platform to a Motorola platform since these functions are not standard ANSI and will need to converted for the Motorola Platform.  Below is shown an example for a 8255 IO board configured at a base address 0x2b4
 
 #include stdio.h
 #include dos.h
 
void main()
{
     Date: 26th August 1992 
    Version 1.0 
    Function : Reads port A and display it on the screen and portb,c       
     Modifications:  Non Standard non portable code PC only
    */
 
  int CardAddress = 0x2b0, BaseAddress, Port_a;
  int  Port_b, Port_c, ControlRegister;
  unsigned char ControlWord = 0x90, InputValue;
 
   BaseAddress = CardAddress + 4;
   Port_a = BaseAddress;
   Port_b = BaseAddress + 1;
      Port_c = BaseAddress + 2;
      ControlRegister = BaseAddress + 3;
    
      ControlWord = 0x90;
    
   outportb(ControlRegister, ControlWord);
    
   while (1)
   {
      InputValue = inportb(Port_a);
      outportb(Port_b, InputValue);
      outportb(Port_c, InputValue);
        
        printf("Read from A = %x\n", InputValue);
    }
}    
 
Despite these additions NON-ANSI functions they are only DOS commands and hence using Windows NT you will need to write a windows driver, for this you will need C++ and a few books on Windows.


Related Discussions:- Standard input- output using motorola and intel devices

Flow chart, flow chart for calculating the volume of sphere

flow chart for calculating the volume of sphere

Program for dynamic 2d memory, Requirements: 1.  This assignment as well...

Requirements: 1.  This assignment as well as other assignments in this class must be finished on Windows operating system. 2.  Zip your program and submit the zip file on ANG

Help me for an programming contest .., Pebble Merchant Problem Description...

Pebble Merchant Problem Description There is a pebble merchant. He sells the pebbles, that are used for shining the floor. His main duty is to take the length of the room’s sides

#title.digital clock, Write a program to print a digital clock which displa...

Write a program to print a digital clock which displays the time for 2 hours .

For loop, minimum of seven number

minimum of seven number

Explain briefly about class and objects, Question 1. Explain Briefly ab...

Question 1. Explain Briefly about class and objects. 2. Create a class string which stores a string value. Overload ++ operator which converts the characters of the string t

, Question 1 / 1 You have an N x N chessboard and you wish to place N king...

Question 1 / 1 You have an N x N chessboard and you wish to place N kings on it. Each row and column should contain exactly one king, and no two kings should attack each other (two

C program to add, C program to add, average and deviation of numbers: v...

C program to add, average and deviation of numbers: void main() {                 int sum=0,a[10],i;                 float avg=0,dev,vari=0,var;                 pri

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