Intel 64 and IA-32 Architectures Software Developers Manual Volume 3A, System Programming Guide, Part 1

Vol. 3A 8-27
ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (APIC)
destination field set to FH for Pentium and P6
family processors and to FFH for Pentium 4
and Intel Xeon processors.
11: (All Excluding Self)
The IPI is sent to all processors in a system
with the exception of the processor sending
the IPI. The APIC broadcasts a message with
the physical destination mode and destina-
tion field set to 0xFH for Pentium and P6
family processors and to 0xFFH for Pentium
4 and Intel Xeon processors. Support for this
destination shorthand in conjunction with
the lowest-priority delivery mode is model
specific. For Pentium 4 and Intel Xeon pro-
cessors, when this shorthand is used togeth-
er with lowest priority delivery mode, the IPI
may be redirected back to the issuing pro-
cessor.
Destination Specifies the target processor or processors. This field is only
used when the destination shorthand field is set to 00B. If the
destination mode is set to physical, then bits 56 through 59
contain the APIC ID of the target processor for Pentium and P6
family processors and bits 56 through 63 contain the APIC ID of
the target processor the for Pentium 4 and Intel Xeon proces-
sors. If the destination mode is set to logical, the interpretation
of the 8-bit destination field depends on the settings of the DFR
and LDR registers of the local APICs in all the processors in the
system (see Section 8.6.2, “Determining IPI Destination”).
Not all combinations of options for the ICR are valid. Table 8-3 shows the valid combi-
nations for the fields in the ICR for the Pentium 4 and Intel Xeon processors; Table
8-4 shows the valid combinations for the fields in the ICR for the P6 family proces-
sors. Also note that the lower half of the ICR may not be preserved over transitions
to the deepest C-States.
Table 8-3. Valid Combinations for the Pentium 4 and Intel Xeon Processors’
Local xAPIC Interrupt Command Register
Destination
Shorthand
Valid/
Invalid
Trigger
Mode Delivery Mode
Destination
Mode
No Shorthand Valid Edge All Modes
1
Physical or Logical
No Shorthand Invalid
2
Level All Modes Physical or Logical
Self Valid Edge Fixed X
3
Self Invalid
2
Level Fixed X