Datasheet

Intel
®
Itanium
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Processor 9300 Series and 9500 Series Datasheet 17
Introduction
The Intel QPI viral and poison fields are used to flag corrupted system state and bad
data accordingly. Once it has “gone viral”, an Intel QPI agent will set the viral field
within all packet headers. Viral mode is entered in three ways: receiving a viral packet,
upon a detecting fatal/panic error, or when a global viral signal (from Cboxes) is
asserted. Viral is cleared on Reset. Poisoning is used to indicate bad data on a per-flit
basis. Poison does not indicate corrupted system coherency, but rather that a particular
block of data is not reliable.
Intel
®
Itanium
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Processor 9500 Series PAL's Demand Based Switching (DBS) support
includes implementations of Power/Performance states (P-states) and Halt states (C-
states). For the PAL Halt state interface and architected specifications of the PAL P-
state interface, see the Intel
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Itanium
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Architecture Software Developer's Manual,
Volume 2, Section 11.6. PAL controls the Intel
®
Itanium
®
Processor 9500 Series
processor power through a special built-in microcontroller that manipulates voltage and
frequency. PAL communicates requested P-states to this controller through internal
registers.
As shown in Figure 1-3, Itanium architecture-based firmware consists of several major
components: Processor Abstraction Layer (PAL), System Abstraction Layer (SAL),
Unified Extensible Firmware Interface (UEFI) and Advanced Configuration and Power
Interface (ACPI). PAL, SAL, UEFI and ACPI together provide processor and system
initialization for an operating system boot. PAL and SAL provide machine check abort
handling. PAL, SAL, UEFI and ACPI provide various run-time services for system
functions which may vary across implementations. The interactions of the various
services that PAL, SAL, UEFI and ACPI provide are illustrated in Figure 1-3. In the
context of this model and throughout the rest of this chapter, the System Abstraction
Layer (SAL) is a firmware layer which isolates operating system and other higher level
software from implementation differences in the platform, while PAL is the firmware
layer that abstracts the processor implementation.
Figure 1-2. Intel
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Itanium
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Processor 9500 Series Processor Block Diagram