Re: [ECOS] Example ISR,DSR for ARM AEB-1

[Jonathan Larmour <jlarmour at redhat dot co dot uk>]

k e wrote:
> 
> Can anyone recommend a source for a simple example
> program for the AEB that shows how to create
> an ISR and DSR?  I'd like to have a thread respond
> to a low frequency external interrupt.  I'd like to
> keep all of the other drivers on the board which
> are being used by other threads running.  Is there
> a means by which I can identify a specific external
> interrupt to cause a specific DSR to be called
> without having to figure out all of the other DSR's
> that are being called by the default ISR?.
> 
> Here's the simple application that I'd like to code
> up:
>   external interrupt 0 (which is wired to a switch
>      on the AEB-1) would cause a DSR that would toggle
>      an LED.

I've attached something I quickly knocked up based on an old example of
mine. I haven't compiled it, so expect any sort of problems with it :-).

It should give you an idea of what's going on.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault
#include <cyg/kernel/kapi.h>
#include <stdio.h>
#include <cyg/hal/hal_intr.h>

volatile int i=0;

/* this is the ISR for ext 0 interrupts */
cyg_uint32 int_0_isr(cyg_vector_t vector, cyg_addrword_t data)
{
  /* ISRs must acknowledge the interrupt, or they might be invoked
     again */
  cyg_interrupt_acknowledge(vector);
  return CYG_ISR_CALL_DSR;
}

/* this is the DSR for ext 0 interrupts */
void int_0_dsr(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    i += count;
}



int main( int argc, char *argv[] )
{
  cyg_handle_t int_0_ISR_H;
  cyg_interrupt intr;
  int oldi = 0;

   /* create an interrupt handler with int_0_isr() as the ISR
      and int_0_dsr() as the DSR. */

  cyg_interrupt_create(CYGNUM_HAL_INTERRUPT_EXT0, 0, 0, &int_0_isr, 
                       &int_0_dsr, &int_0_ISR_H, &intr);

  cyg_interrupt_attach(int_0_ISR_H);


  for (;;) {
      if (i != oldi) {
          printf("Now received %d interrupts\n", i);
          oldi = i;
      }
  }
  return 0;
}