RE: Sensing Interrupt Pins that is not in your trace?

[Horkel Milan <m.horkel@decros.cz>]

Be aware of the fact, that INTA# in one slot IS USUALLY NOT connected to
INTA# in the next slot.

In fact it is common to have SLOT1.INTA# connected to SLOT2.INTB# and
SLOT3.INTC# or somethink like this. The reason is not to have all devices
INTA# connected together becase it is better to use as many IRQs (inputs of
interrupt controller) as hardware allows.

Milan Horkel
DECROS
HW development

-----Puvodni zprava-----
Od: Addison Chen [mailto:addison@netconvergence.com]
Odeslano: 26. ledna 2001 2:36
Komu: pci-sig@znyx.com
Poedmit: Sensing Interrupt Pins that is not in your trace?


Hi guys, let me tell you my design dilemma..

I am currently coding firmware for a PCI device that have the ability to
sense interrupts in the PCI backplane.  If I do get an interrupt, the
interrupt handler gets called.

Right now, I want to sense interrupts from other PCI devices on the same
backplane.  The problem is, some of the PCI devices are MULTI-functional
devices that take up 2 or more Interrupt pins (i.e. INTA# and INTB#).  Since
my device (that I am coding) uses only INTA#, it can't see an interrupt
INTB# from a multifunctional device.

Is there any way to be able to sense interrupts from ALL PCI devices?
Currently, I can think of 2 solutions:

1)  Poll the interrupt registers on each device for interrupts.  Solution is
too slow!

2)  Purchase a special PCI backplane that have all INTA#, INTB#, INTC#, and
INTD# connected to the same trace.  That way, the PCI device that I am
coding can detect any interrupts occurring.  BUT, does this special PCI
backplane exists?

Any help would be greatly appreciated.  Thanks.

-Addison