Intel® 82806AA PCI 64 Hub (P64H) Specification Update
This document is an update to the specifications contained in the documents listed in the Affected Documents/Related Documents table. It is a compilation of device and document errata, and specification clarifications and changes, and is intended for hardware system manufacturers and for software developers of applications, operating system, and tools.
Information types defined in the nomenclature section of this document are consolidated into this update document and are no longer published in other documents. This document may also contain information that has not been previously published.
The table indicates the specification changes, errata, specification clarifications, or documentation changes, which apply to the listed 82806AA P64H steppings. Intel intends to fix some of the errata in a future stepping of the component and to account for the other outstanding issues through documentation or specification changes as noted.
Intel® P64H I/O APIC Agent ID
Problem: The P64H can incorrectly increment its I/O APIC agent ID when servicing interrupts under heavy I/O APIC traffic. This can cause the P64H to incorrectly drive an I/O APIC message when another agent (i.e., ICH) is performing an operation on the I/O APIC lines.
Implication: When this collision occurs the I/O APIC message, including the interrupt vector, can be corrupted. If the message is corrupted the processor will execute the incorrect interrupt service routine. The processor will also respond with an end of interrupt message with operation. This will lead to stuck level triggered interrupts and edge triggered interrupts that are not serviced.
Read the full Intel® 82806AA PCI 64 Hub Specification Update.