Specifications

PC BIOS
10-6 PP 41x/03x
The interrupt controller in the 6300ESB ICH can operate in two basic modes, namely PIC (or Non-
APIC) mode and APIC mode. PIC mode corresponds to the legacy PC interrupt structure. APIC
mode provides additional interrupts and several functional improvements.
Table 10-1 lists the allocation of the various PCI and PCI Express devices to interrupt inputs on the
6300ESB ICH. These allocations are fixed and cannot be changed by the user.
ICH
Interrupt
Input
Device(s) on Rev C Boards Device(s) on Rev B Boards
PIRQA
SM722 Graphics
Ethernet Channel 0
Ethernet Channel 1
Ethernet Channel 2
CompactPCI Bridge (Peripheral only)
PMC Site 2 INTC
XMC Site
CompactPCI INTA (System Controller)
SM722 Graphics
Ethernet Channel 0
Ethernet Channel 1
Ethernet Channel 2
CompactPCI Bridge (Peripheral only)
PMC Site 2 INTA
XMC Site
CompactPCI INTA (System Controller)
PIRQB
PMC Site 2 INTD
CompactPCI INTB (System Controller)
PMC Site 2 INTB
CompactPCI INTB (System Controller)
PIRQC
PMC Site 2 INTA
CompactPCI INTC (System Controller)
PMC Site 2 INTC
CompactPCI INTC (System Controller)
PIRQD
PMC Site 2 INTB
CompactPCI INTD (System Controller)
PMC Site 2 INTD
CompactPCI INTD (System Controller)
PIRQE
PMC Site 1 INTA PMC Site 1 INTA
PIRQF
PMC Site 1 INTB PMC Site 1 INTB
PIRQG
PMC Site 1 INTC PMC Site 1 INTC
PIRQH
PMC Site 1 INTD PMC Site 1 INTD
Table 10-1 PCI Device Interrupt Allocations
Table 10-2 lists the typical interrupt structure in PIC mode. A total of 15 usable interrupts are
available. The actual allocation of PCI bus interrupts to available interrupt controller inputs will
depend on both the default “Plug-and-play” settings programmed by the PC BIOS, and the way in
which the user has overridden them using the Setup screens. When more than one PCI bus
interrupt is routed to the same interrupt controller input, that input will remain active while any of the
sources connected to it are active.
Interrupt Device(s)
IRQ0 Timer 0
IRQ1 Keyboard
IRQ2 Slave PIC
IRQ3 Serial Port COM2
IRQ4 Serial Port COM1
IRQ5 Combined Interrupt (IPMI + PIT + CompactPCI
M66EN transition + CompactPCI ENUM#)
IRQ6 Floppy Disk Controller (AD PP5/001 Super I/O)
IRQ7 Parallel Port (AD PP5/001 Super I/O)
IRQ8 Real Time Clock
IRQ9 PCI device interrupt
IRQ10 PCI device interrupt
IRQ11 PCI interrupt
OR Serial Ports COM3 + COM4 (AD PP5/001
Super I/O)
IRQ12 Mouse
IRQ13 Floating Point Error
IRQ14 Primary IDE
IRQ15 Secondary IDE
Table 10-2 Interrupt Structure in PIC Mode