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

Basic data type in cpp, B a s i c D a t a t y p e : ...

B a s i c D a t a t y p e : T h e r e a r e t h r e e t y p e o f d a t a t y p e i n C+ + 1.       P r

C++ age guessing game, Write a program that predicts users’ age (0-128 year...

Write a program that predicts users’ age (0-128 years old) with at most 7 questions. The game starts with asking the user whether he/she is younger or older than G (an initial gues

Write a program of constructors and destructors, Write a program of constru...

Write a program of constructors and destructors Make a class drugs having encapsulated data for medicine name, whether solid or liquid, price and purpose of use. From this clas

Arrays, how to declare multi dimensional array

how to declare multi dimensional array

Board coloring, coloring of elements in matrix form inm particular matrix.t...

coloring of elements in matrix form inm particular matrix.the color should not match with another color.

C language, WHAT IS A C LANGUAGE? C IS A PROGRAMMING?

WHAT IS A C LANGUAGE? C IS A PROGRAMMING?

Constructors and destructors, Constructors and Destructors: A Class is ...

Constructors and Destructors: A Class is defined as constructor by declaring a constructor in the form of function inside the class.  In other word a function in the name of

How can one encourage his (older) compiler , Q: How can one encourage his (...

Q: How can one encourage his (older) compiler to check new to see automatically if it returns NULL?       A: His compiler eventually will. If he contain an old compiler wh

Doubt!, find the greater of the two variables, without using conditional lo...

find the greater of the two variables, without using conditional loops or ternary operators?

Write a program that takes the image, Write a program that takes the image ...

Write a program that takes the image tracks.jpg and finds Canny edges, and then finds lines in these edges using the Hough transform. The easiest way to do this is to take the prog

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