From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfram Kattanek <wolfram.kattanek@imms.de>
To: Carlos Eduardo dos Reis Rodrigues Sobrinho <epilog@netc.pt>
Cc: eCos Discuss <ecos-discuss@sourceware.cygnus.com>
Subject: Re: [ECOS] Build eCos and Handle/Interrupts problems
Date: Thu, 01 Mar 2001 02:38:00 -0000
Message-id: <983443086.3a9e268e1013c@imp.imms.de>
References: <00d501c0a158$d9137960$35bd12d4@netc.pt> <3A9CB01C.E0075686@redhat.com> <003a01c0a234$f53898a0$24bd12d4@netc.pt>
X-SW-Source: 2001-03/msg00006.html

Carlos Eduardo dos Reis Rodrigues Sobrinho <epilog@netc.pt>:

> > > I also have some questions about interrupts and handles like how can I
> make
> > > a program with two threads, one that printf the cosine of a number and
> the
> > > other one (don't know if i need another one or if one thread is enough)
> that
> > > is only active when the push button of the AEB is pressed for
> example.The
> > > one near the reset button.
> >
> > You mean the interrupt button? That only delivers an interrupt. Even if
> you
> > configure it to be level triggered (rather than edge triggered) it would
> > mean getting far too many interrupts while the button is depressed.
> >
> > If my understanding is wrong, then find out what interrupt the button is
> > associated with, and write an application using the kernel C API that
> > attaches an ISR and DSR to that interrupt. In the DSR, suspend the thread
> > whatever way you like depending on what its doing (and whether it needs to
> > finish it whenever the button is released).
> 
> Sorry to being so anoying but could you or anyone give me and example of
> using and interrupt to call a thread
> Thanks

Here's code snippet which probably will help you:

#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)
{
  /* put your code here; for details of ISRs and DSRs see eCos documentation */
  /* the following serves only as an example: */
    i += count;
}

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

  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;
}


Wolfram
--
Wolfram 'L.A.' Kattanek     Institut fuer Mikroelektronik- und
Email:       LA@imms.de     Mechatronik-Systeme (IMMS) gGmbH     
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