Modifying RTX PCI Device Properties

You can change a PCI device’s interrupt level (IRQ) and select its Disposition, that is, whether it can share an interrupt level with other RTX devices. IRQ's are required for any PCI devices (both MSI-capable and non-MSI-capable) that will be attached to using line-based interrupts.

NOTE: You cannot modify device resources on non-ACPI Windows systems.

To modify a PCI device's properties:

Open the RTX Properties Control Panel.
On the Hardware tab, click the Settings button under RTX devices. You'll see a list of the current Plug and Play devices on your system. If Show filtered list is checked, only the most common devices are displayed; if it is unchecked, all devices are displayed. To update the device information, click the Refresh button.
Double-click the device whose properties you want to edit. You see the RTX PCI Device Properties dialog box.

RTX PCI Device Properties for MSI-capable devices
If the device you are viewing is an MSI-capable device, you will see a message beginning with "Device is MSI capable..." in the Status area. If you only want to use message-based interrupts with this device, no configuration is necessary and you can click OK or Cancel to close the RTX PCI Device Properties dialog box. If you want to use line-based interrupts with this MSI-capable device, click Obtain line based resources and proceed to step 6.

NOTE: By configuring both line-based and message-based interrupts for an MSI-capable device, you make it possible for some RTSS applications to communicate with the device via line-based interrupts while others use message-based interrupts. However, you cannot attach to a device using message-based and line-based interrupts at the same time. If multiple applications attach simultaneously to a single MSI-capable device, they must all use the same interrupt type.

Non-MSI devices are configured to obtain line-based resources by default. If you are configuring a non-MSI device and do not want it to obtain line-based resources, deselect Obtain line-based resources and proceed to step 7. Otherwise, proceed to step 6.

NOTE: Some applications communicate with non-MSI devices by other means, for example, polling. In these cases, deselecting Obtain line-based interrupts frees up line-based resources for use by other devices.

To configure a device to use line-based interrupts, do the following:

Enter an unused interrupt value in the IRQ box. For instructions on how to check IRQ availability, click here. If you do not require a specific IRQ value, you can enter the value 0 and the subsystem will provide you with an IRQ if one is available.
Select a disposition from the Disposition menu:

Device Exclusive (default) requests that the IRQ value is exclusive to this device. No other plug and play devices can share this IRQ.
Shared by RTX allows the IRQ value to be shared.

Not all PCI slots can be set to an IRQ disposition of Device Exclusive. If you want your interrupt device to have an unshared IRQ, you should try to locate an empty, unshared PCI slot. Some interrupt devices, such as PCI NIC devices, may need an unshared, bus-mastering PCI slot. It may take several tries to figure out the right slot.

Click OK to close the RTX Device Properties dialog box and then click Apply or OK in the PnP Device Settings dialog box.
Reboot the machine so your IRQ changes take effect.
To verify that there is no resource conflict with the requested IRQ, go to the Hardware tab in RTX Properties, double-click the device you just updated, and check to see if it is working properly.