Intel MultiProcessor - Virtual Wire Mode Via I;O APIC

MultiProcessor Specification
3-10 Version 1.4
Figure 3-3 shows how Virtual Wire Mode can be implemented through the BSP’s local APIC. It is
also permissible to program the I/O APIC for Virtual Wire Mode, as shown in Figure 3-4. In this
case the interrupt signal passes through both the I/O APIC and the BSP’s local APIC.
LINTIN0 LINTIN1
NMI
NMI
INTR
CPU 1
LINTIN0 LINTIN1 LINTIN0 LINTIN1
NMI INTR
CPU 2
NMI INTR
CPU 3
REG.
MARK
BSP AP1 AP2
LOCAL
APIC
1
LOCAL
APIC
2
LOCAL
APIC
3
RESET
LINTIN0
LINTIN1
ICC BUS
INTR
I/O
APIC
8259A-
EQUIVALENT
PICS
INTERRUPT INPUTS
SHADED AREAS INDICATE UNUSED CIRCUITS. DOTTED LINE SHOWS INTERRUPT PATH.
Figure 3-4. Virtual Wire Mode via I/O APIC