RTEMS 4.5.0 On-Line Library

Console Driver InterruptHandler

BSP and Device Driver Development Guide

8.4.2.1: InterruptHandler

The InterruptHandler is responsible for processing asynchronous interrupts from the UART. There may be multiple interrupt handlers for a single UART. Some UARTs can generate a unique interrupt vector for each interrupt source such as a character has been received or the transmitter is ready for another character.

In the simplest case, the InterruptHandler will have to check the status of the UART and determine what caused the interrupt. The following describes the operation of an InterruptHandler which has to do this:

rtems_isr InterruptHandler (rtems_vector_number v)
{
  check whether there was an error

  if some characters were received:
     Ask Termios to put them on his input buffer

  if some characters have been transmitted
        (i.e. the UART output buffer is empty)
     Tell TERMIOS that the characters have been
     transmitted. The TERMIOS routine will call
     the InterruptWrite function with the number
     of characters not transmitted yet if it is
     not zero.
}

BSP and Device Driver Development Guide