Irq Settings; System Board Pci Slots - HP NetServer LC 2000r Installation Manual

Chapter 6

IRQ Settings

The IRQ settings are automatically assigned and don't require user intervention.
PCI boards have the capability of sharing hardware interrupts (IRQs) with other
PCI boards, as stated in the PCI specifications, but this does not always prove to
be true between board manufacturers. To solve this problem requires an in-depth
knowledge of a server's implementation to place a PCI board in a slot that would
not conflict with another PCI board's IRQ setting.
The HP NetServer provides various ways to automatically share interrupts in the
NetServer. The sharing mode can be selected under the heading "Sharing
Algorithms" in the Setup Utility. The IRQs are automatically assigned during boot
up for each PCI slot and embedded device in the NetServer, avoiding any IRQ
conflicts and providing the best performance. This feature also provides a way of
manually assigning IRQs when disabling the Sharing Algorithm feature. Refer to
Chapter 10, "Configuring the HP NetServer," for more information.
These IRQ assignments trigger the installed NOS to enable the APIC (Advanced
Programmable Interrupt Controller) which takes control of the IRQ sharing
scheme. You are not required to manually assign interrupts for the following
NOSs:
l Microsoft's NT 4.0
l Novell's NetWare 5
l SCO UnixWare 7
NOTE
SCO UnixWare 7 requires installation of the OSMP module to
enable the APIC mode.

System Board PCI Slots

All accessory boards plug into the six slots on system board at the rear of the
NetServer's chassis. See Figure 6-1.
Four PCI slots (P1-P4) support full length 32-bit boards at a clock rate of
33 MHz. These slots only support +5 VDC power and Universal boards.
These slots have keys in the upper half of the board slot to prevent 3.3 volt
boards from being inserted into the slots.
NOTE
Universal boards automatically switch to accept power from a
+5.0 or +3.3 VDC source and have a key slot in the connector
to allow installation in any of the 6 PCI slots.
Installing Additional Boards
63