Siemens SIMATIC RI 45 PIII Series Manual page 76

Motherboard
Submenu PCI/PNP
Available means that the IRQ can be allocated to Plug and Play modules or
ISA IRQ Resource
given a motherboard function by the plug and play mechanism of the BIOS.
Exclusion
You should only use the Reserved setting if the interrupt does not have to be
assigned to plug and play ISA modules in the application software. If the
interrupt is "Reserved," it cannot be assigned a PCI slot by the plug & play
mechanism.
Figure 2-21
2-48
PhoenixBIOS Setup Utility.
Main Advanced Security
PCI / PNP ISA IRQ Resource Exclusion
IRQ 3: [Available]
IRQ 4: [Available]
IRQ 5: [Available]
IRQ 7: [Available]
IRQ 9: [Available]
IRQ 10: [Available]
IRQ 11: [Available]
IRQ 15: [Available]
F1 Help Select Item + / -
ESC Exit Select Menu Enter Select
"PCI / PNP ISA IRQ Resource Exclusion" Submenu
Power Boot Sequence
Version
Item Specific Help
Reserves the specified
IRQ for use by legacy
ISA devices
Change Values F9 Setup Defaults
Sub-Menu F10 Save and Exit
C79000-G7076-C817-01
Exit
RI 45 PIII, Manual