* [ECOS] MPC8xxx - cyg_hal_interrupt_acknowledge()
@ 2009-11-25 8:51 Danny Sade
2009-12-18 7:03 ` Paul D. DeRocco
0 siblings, 1 reply; 2+ messages in thread
From: Danny Sade @ 2009-11-25 8:51 UTC (permalink / raw)
To: ecos-discuss
Hi All,
cyg_hal_interrupt_acknowledge( vector ) is composed of lines like
case CYGNUM_HAL_INTERRUPT_IRQ1 ... CYGNUM_HAL_INTERRUPT_IRQ7:
*reg_sipnr_h |= ( (0x00004000) >> (vector - CYGNUM_HAL_INTERRUPT_IRQ1) );
break;
The question is why to use the |= operator? When an interrupt is pending, the corresponding bit
at SIPNR is turned on. Using the |= operator results with writing 1s to all bits which are turned on,
and therefore acknowledging all pending interrupts...
Am I missing something here?
Thanks
Danny
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
^ permalink raw reply [flat|nested] 2+ messages in thread
* RE: [ECOS] MPC8xxx - cyg_hal_interrupt_acknowledge()
2009-11-25 8:51 [ECOS] MPC8xxx - cyg_hal_interrupt_acknowledge() Danny Sade
@ 2009-12-18 7:03 ` Paul D. DeRocco
0 siblings, 0 replies; 2+ messages in thread
From: Paul D. DeRocco @ 2009-12-18 7:03 UTC (permalink / raw)
To: eCos Discuss
> From: Danny Sade
>
> Hi All,
> cyg_hal_interrupt_acknowledge( vector ) is composed of lines like
> case CYGNUM_HAL_INTERRUPT_IRQ1 ... CYGNUM_HAL_INTERRUPT_IRQ7:
> *reg_sipnr_h |= ( (0x00004000) >> (vector -
> CYGNUM_HAL_INTERRUPT_IRQ1) );
> break;
>
> The question is why to use the |= operator? When an interrupt is
> pending, the corresponding bit
> at SIPNR is turned on. Using the |= operator results with
> writing 1s to all bits which are turned on,
> and therefore acknowledging all pending interrupts...
>
> Am I missing something here?
Yes. Read it again. Looks fine to me.
--
Ciao, Paul D. DeRocco
Paul mailto:pderocco@ix.netcom.com
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-12-18 7:03 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-11-25 8:51 [ECOS] MPC8xxx - cyg_hal_interrupt_acknowledge() Danny Sade
2009-12-18 7:03 ` Paul D. DeRocco
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).