RE: Interrupt-Ack-Cycle required for host bridge?

["Prakash Chauhan" <pchauhan@egenera.com>]

The interrupt acknowledge cycle is used by Intel CPU's to get the interrupt
vector from the 8259 interrupt controller.  If the processor uses an
alternative means to determine which interrupt occurred and which Interrupt
service routine to call in response to an interrupt then the Interrupt
Acknowledge cycle would not be needed.  I would think that would be the case
if the processor and the PCI bus controller are on the same chip.

-----Original Message-----
From: Heiner, Andreas [mailto:HeinerA@Becker.de]
Sent: Wednesday, October 16, 2002 10:43 AM
To: pci-sig@znyx.com
Subject: Interrupt-Ack-Cycle required for host bridge?


Dear experts,


I have just had a discussion with our processor manufacturer.

The processor includes a host pci bridge, but is not capable to generate
Interrupt-Ack Cycles on the PCI bus.

In the spec is written, that the bus supports an Interrupt Ack cycle. Does
this means that the host bridge must be capable to generate it to be PCI
compliant?

Regards,

Andreas Heiner
Becker Automotive Systems
Germany

--------------------------- End of mail -------------------------------