Psudo code for interrupt handler , C/C++ Programming

Assignment Help:

The rPeANUt simulator provides buffering of the characters that are typed into the terminal. However, this would generally not be the case so if the program did not consume a character before the next one is typed then a character may be lost. So in this next part of the lab you are required to write an interrupt handler for the IO terminal that will capture characters as they are typed and place them in a buffer. The read system call would then read them out of this buffer rather than directly from the device. The psudo code for interrupt handler with a single character buffer:

void iohandler () {

   if (buffcount == 0) {

      buff = getchar();  // no need to poll on the status register

      buffcount = 1;

   } else {

      getchar(); // no room in the buffer so we lost a character!!!

   }

   enableInterrupts();

}

void traphandler ()  {

   enableInterruptes();

   if (R0 == 0) { // read system call

      while (buffcount == 0) ;

      R1 = buff;

      buffcount = 0;

   } else if (R0 == 1) { // write system call

      putchar(R1); // just store R1 to memory location 0xfff0

   }

}

char buff;

int buffcount;

void main() {

   buffcount = 0;

   enableIOterminalInterrupts();  // involves writing to the control register of the IO terminal device.

   char c;

   while (1) {

      c = read();

      write(c);

   }

}

 


Related Discussions:- Psudo code for interrupt handler

Arrays, how to write the code for operation research

how to write the code for operation research

Described storage qualifiers in c++ ?, A: They are following: Const: poi...

A: They are following: Const: point out that memory once initialized, must not be modify through a program. Volatile: denote that value in the memory location can be modified

Define a function in c program, Define a function in c program: int f1...

Define a function in c program: int f1() { static int x=10; return x; } int f2() { int y=5; return y; } extern int z; void f()     {

Program decision making instructions, Within programs we very often want to...

Within programs we very often want to execute a different section of code, depending upon various conditions within C the If statement is used to achieve this. The If statement con

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

Creating shopping carts, how to create a shopping cart and sibmit the code ...

how to create a shopping cart and sibmit the code segment on screan

Beginning C++ Through Game Progammin, you are to create a text adventure ga...

you are to create a text adventure game that uses pointers. You have a rich, eccentric Uncle Billy who is soon to be deceased. How soon.....oops......he''s gone. He has left yo

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