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PCI/IRQ Sharing

Here are the details of the VP6 PCI/IRQ sharing assignments, per the VP6 manual:

Signals PCI-1 PCI-2 PCI-3 PCI-4 PCI-5 HTP370

PIRQ_0 Assignment INT A INT B INT B INT D INT C INT C

PIRQ_1 Assignment INT B INT D INT A INT A INT D X

PIRQ_2 Assignment INT C INT C INT D INT B INT A X

PIRQ_3 Assignment INT D INT A INT C INT C INT B X

USB used INT D

Each PCI slot has four INT's (INT A ~ INT D), and the AGP slot has two INT# (INT A and INT B)

PCI-1 shares IRQ with the AGP slot.

PCI-4 and USB controllers share an IRQ.

If you want to install two PCI cards into those PCI slots that share (an) IRQ with one another at the same time, you must make sure that your OS and PCI device drivers support (the) IRQ sharing function.

PCI slot 5 shares IRQ signals with the HPT370 IDE controller (supports ATA/100). The driver for HPT370 IDE controller supports IRQ sharing with other PCI devices. But if you install a PCI card that doesn't allow IRQ sharing with other devices into PCI slot 5, you may encounter some problems. Furthermore, if your Operating System doesn't allow peripheral devices to share IRQ signals with each other, such as Windows NT for example, you can't install a PCI card into PCI slot 5.

(The) HPT370 IDE controller is designed to support high-speed and high performance mass storage devices. Thus we suggest that you don't connect non-disk drives that use ATA/ATAPI interfaces, such as CD-ROM to HTP370 IDE connector (IDE-3 & IDE-4).

Taken from the VP6 manual, chapter 3, page 13.

Hope this helps,

Spanky