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Re: PCI Interrupts

At 07:09 AM 9/26/96 PDT, you wrote:
[stuff deleted]
>
>1.  I think I have put in the interrupt handler correctly at the right
>    place, but it was never called.  What else could be wrong?
>

Did you unmask the slave PIC (8259) for IRQ 10? You need to clear bit 2,
port A1h (IN AL, A1h; AND AL, 11111011B; OUT A1h, AL). Do this before
installing your interrupt handler (ISR).

>2.  There is a PCI BIOS call SET_PCI_HW_IRQ.  My code shouldn't need to set
>    this up though.  The Plug-and-Play BIOS should have done this already.
>    Is this correct?
>
Yes. The BIOS call is to re-route the interrupt to a different IRQ. Leave
it as is (the BIOS has already done the IRQ routing for you).

>3.  I want to use the GET_ROUTING_OPTIONS PCI BIOS call to check the
>    IRQ routing settings.  The call was returned with no errors but the
>    routeBuffer data structure was not changed at all.  Does anyone has
>    some sample code to show how this call can be done under Phar Lap?
>
Can't help you here. This table doesn't really contain any info that would
help you. The routing info is static & mostly used to see how the
slot-to-slot interrupt line routing is handled.

>4.  Can I probe on the motherboard somewhere to see if IRQ-10 is happening
>    or not?
>
Sure. Hook a 'scope up to pin 6 on Side A of your card (six 'fingers' from
the rear of the card, non-component side). If you want to pick up _your
INTA#_ on an unused slot, this is where you'll need the PCI routing info
table, to see which INTx# line is wired to your slots' INTA#.

>Thank you very much.
>+-----------------------------------------+----------------------------+
>| Henry Lau                               | Phone: 619-674-5000 x222   |
>| Director of Software Development        | Fax:   619-674-5005        |
>| METACOMP, Inc.                          | Email: henrylau@cts.com    |
>| 10989 Via Frontera, San Diego, CA 92127 | http://www.metacompinc.com |
>+-----------------------------------------+----------------------------|
>

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