82801BA Datasheet, PDF (308/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

LPC Interface Bridge Registers (D31:F0)
Bit
Description
Delivery Mode—R/W. This field specifies how the APICs listed in the destination field should act
upon reception of this signal. Certain Delivery Modes will only operate as intended when used in
conjunction with a specific trigger mode. These encodings are:
000 = Fixed. Deliver the signal on the INTR signal of all processor cores listed in the destination.
Trigger Mode can be edge or level.
001 = Lowest Priority. Deliver the signal on the INTR signal of the processor core that is executing
at the lowest priority among all the processors listed in the specified destination. Trigger
Mode can be edge or level.
010 = SMI (System Management Interrupt). Requires the interrupt to be programmed as edge
triggered. The vector information is ignored but must be programmed to all zeroes for future
compatibility.
011 = Reserved
100 = NMI. Deliver the signal on the NMI signal of all processor cores listed in the destination.
Vector information is ignored. NMI is treated as an edge triggered interrupt even if it is
programmed as level triggered. For proper operation this redirection table entry must be
programmed to edge triggered. The NMI delivery mode does not set the RIRR bit. Once the
10:8
interrupt is detected, it will be sent over the APIC bus.
If the redirection table is incorrectly set to level, the loop count will continue counting
through the redirection table addresses. Once the count for the NMI pin is reached again,
the interrupt will be sent over the APIC bus again.
101 = INIT. Deliver the signal to all processor cores listed in the destination by asserting the INIT
signal. All addressed local APICs will assume their INIT state. INIT is always treated as an
edge triggered interrupt even if programmed as level triggered. For proper operation this
redirection table entry must be programmed to edge triggered. The INIT delivery mode
does not set the RIRR bit. Once the interrupt is detected, it will be sent over the APIC bus.
If the redirection table is incorrectly set to level, the loop count will continue counting
through the redirection table addresses. Once the count for the INIT pin is reached again,
the interrupt will be sent over the APIC bus again
110 = Reserved
111 = ExtINT. Deliver the signal to the INTR signal of all processor cores listed in the destination
as an interrupt that originated in an externally connected 8259A compatible interrupt
controller. The INTA cycle that corresponds to this ExtINT delivery will be routed to the
external controller that is expected to supply the vector. Requires the interrupt to be
programmed as edge triggered.
7:0
Vector—R/W. This field contains the interrupt vector for this interrupt. Values range between 10h
and FEh.
9-46
82801BA ICH2 and 82801BAM ICH2-M Datasheet