RE: [ECOS] generating interrupts in ARM-PID (SID simulator)

["Robert Cragie" <rcc@jennic.com>]

> > I am trying to generate external interrupts and handle
> > it on a ARM-PID configuration. I am using SID as the
> > simulator for ARM PID.Ofcourse, eCos is my RTOS.
> >
> > >From the SID configuration file, I understand that
> > there is a interrupt controller which can be
> > associated with 32 interrupts.One of the output pins
> > of the interrupt controler is connected to the "nirq"
> > pin of the processor.
> > I use one the the interrutpt sources numbered "16" to
> > associate with an event whose occurance I want to
> > count.

Only interrupts up to 15 can be handled by the interrupt controller (well,
according to the PID manual anyway). Try connecting to interrupt number 11.
This corresponds to the ASB0 interrupt, which seems to be unconnected in
SID.

So in configrun-sid:

connect-pin sensor-sched 1-event -> intrctrl source-11

However, note that the inputs to the ARM interrupt controller are level
interrupts. If the scheduler generates a pulse, it could either get missed
(short pulse) or cause continuous interruption problems (long pulse). So
ideally in either case you'd want to latch the rising edge of the scheduler
output and have some mechanism to clear the it in the DSR somehow. I'm not
sure how you'd do this is SID, though.

> > Now, the problem is that I am unable to catch the
> > interrupt and process it using an ISR. Specifically, I
> > register my own ISR at the the vector 16. However, it
> > seems that I am unable to catch the interrupt.
> >
> > Could anyone kindly advise where I am making the
> > mistake? Also, I m unable to figure out that if and
> > how eCos can be configured to use the 32 interrupts.
> > Afterall, there is only one nirq line. How are the 32
> > interrupts mapped? When, I check the hal_intr.h file,
> > I find that at max there can be 8 interrupts.

Try something like the following to add a handler for interrupt number 11
(ASB0):

#include <cyg/kernel/kapi.h>
#include <cyg/hal/hal_intr.h>

/* IRQ handler object */

typedef struct tagIRQ_s
{
    CYG_WORD       tNum;
    cyg_interrupt  sIRQrsrc;
    cyg_handle_t   hIRQ;
} IRQ_s;

static IRQ_s s_sMyIRQ;

/* snip */

cyg_uint32 myISR(cyg_vector_t tVector, cyg_addrword_t tData)
{
    /* Nothing to do in ISR apart from the mandatory procedures */

    /* Stop any further interrupts until handled */
    cyg_interrupt_mask(tVector);

    /* Acknowledge to system (this MUST be done) */
    cyg_interrupt_acknowledge(tVector);

    /* Cause DSR to be run */
    return CYG_ISR_CALL_DSR;
}

cyg_uint32 myDSR(cyg_vector_t tVector, cyg_ucount32 u32Count, cyg_addrword_t
tData)
{
    /* DO YOUR INTERRUPT PROCESSING HERE */

    /* Finally reenable interrupts */
    cyg_interrupt_unmask(tVector);
}

/* snip - somewhere in your initialisation .... */

    s_sMyIRQ.tNum = CYGNUM_HAL_INTERRUPT_ASB0; /* 11 */

    /* First, create and attach the Interrupt handlers */
    cyg_interrupt_create(s_sMyIRQ.tNum,                 /* Interrupt number
*/
                         99,                            /* Priority - what
goes here? */
                         (cyg_addrword_t)&s_sMyIRQ,     /* Data item passed
to interrupt handler - whatever you want */
                         myISR,                         /* ISR */
                         myDSR,                         /* DSR */
                         &s_sMyIRQ.hIRQ,                /* (ptr. to)
Handle - filled in */
                         &s_sMyIRQ.sIRQrsrc);           /* (ptr. to)
Resource reqd. by interrupt */

    cyg_interrupt_attach(s_sMyIRQ.hIRQ);

    /* Finally, enable the interrupt */
    cyg_interrupt_unmask(s_sMyIRQ.tNum);

-----------------------
Hope this helps

Robert Cragie, Design Engineer
_______________________________________________________________
Jennic Ltd, Furnival Street, Sheffield, S1 4QT,  UK
http://www.jennic.com  Tel: +44 (0) 114 281 2655
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