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

Structure, Write a function that calculates the number of elapsed days betw...

Write a function that calculates the number of elapsed days between two dates. For example the days between Feb 3, 1970 and June 21, 1980? Becareful for the Leap year

#compiler design limiting instrutions, Ravi is a newbie to the programming ...

Ravi is a newbie to the programming and while learning the programming language he came to know the following rules: · Each program must start with ''''''''{'''''''' and end wi

Program to create a query from database, Implement (a part of) electronic e...

Implement (a part of) electronic election Scenario where following political parties are participating in election: PPP, PML and PTI.  Create a class PollingStation where it stor

COMPUTER, THEORY OF A COMPUTER PROGRAMMING

THEORY OF A COMPUTER PROGRAMMING

Tool for checking memeory leak, what would be the best tool for debuggingg ...

what would be the best tool for debuggingg memory leaks in c/c++ programming

Pebble merchant problem, Problem Description There is a pebble merchant. H...

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. But he sometime

Simple program of c++ , Simple program of c++: int main() {    i...

Simple program of c++: int main() {    int   bushels;    float dollars, rate;                 cout                 cin >> dollars;                 cout

Pattern, enter height of the shape: 1 3 5 3 1 3 5 7 5 3 5 7 9 7 5 3 5 7...

enter height of the shape: 1 3 5 3 1 3 5 7 5 3 5 7 9 7 5 3 5 7 5 3 1 3 5 3 1

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