82093AA Datasheet, PDF (14/20 Pages) Intel Corporation – I/O ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (IOAPIC)

82093AA (IOAPIC)
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4.0. FUNCTIONAL DESCRIPTION
4.1. INTIN23/SMI# and SMIOUT# Functionality
The SMI# interrupt pin can be routed through the IOAPIC device. The redirection table entry can be
programmed to send an SMI# interrupt over the APIC bus. The SMI# input is sent over the APIC bus when the
delivery mode register is set to 010 for INTIN23/SMI# input and the Mask bit is set to 0. During this time, the
SMIOUT# pin is inactive. If the Mask bit is set to 1, the INTIN23/SMI# input is routed to the SMIOUT# pin on the
IOAPIC. Refer to Figure 3.
If the SMI# routing feature is not desired, the SMIOUT# pin is not connected to SMI# of the CPU’s. The
SMIOUT# pin is left open in the system. The INTIN23/SMI# redirection table entry has the same functionality as
all other redirection table entries.
31
17 16 15 14 13 12 11 10
87
0
Mask
Delivery
010=SMI
Vector
INTIN23/SMI#
Mask Bit
0=APIC Bus
1=SMIOUT#
SMIOUT#
APIC_IR
Figure 3. INTIN23/SMI# Routing And Control From Redirection Table Mask Bit
14
PRELIMINARY