Intel Xeon Processor and Intel E7500/E7501Chipset Compatible Platform Design Guide

Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide 113
Intel
®
82870P2 (P64H2)
Intel
®
82870P2 (P64H2) 8
The 82870P2 (P64H2) is a peripheral chip that performs PCI/PCI-X bridging functions between
the Hub Interface 2.0 and the PCI bus. The P64H2 is an integral part of the E7500/E7501 chipset,
bridging the MCH and the PCI/PCI-X bus. On the primary bus, the P64H2 uses a 16-bit data bus to
interface with the Hub Interface 2.0, and on the secondary bus, it supports two, 64-bit PCI/PCI-X
bus segments. Either of the secondary PCI/PCI-X bus interfaces can be configured to operate in
PCI or PCI-X mode. Each PCI/PCI-X interface contains an I/OxAPIC with 24 interrupts and a Hot-
Plug controller that supports each PCI/PCI-X bus segment.
8.1 PCI/PCI-X Design Guidelines
The P64H2 contains two PCI/PCI-X Interfaces. The PCI Interface has a 33-/66-MHz bus speed,
and the PCI-X interface has a 66-/100-/133-MHz bus speed (see Table 8-1).
NOTE: Frequencies specified are not the only ones supported, rather the maximum allowed in the
configuration.
Intel simulated the PCI/PCI-X bus topologies shown in Section 8.1.2 and Section 8.1.3. If a
platform implements a PCI/PCI-X topology not found in the following sections, it is the
responsibility of the system designer to ensure the system meets the specified timings. The
recommended lengths specified are not intended to replace thorough system simulations and
validation.
Table 8-1. PCI/PCI-X Frequencies
PCI
Frequency Maximum Slots Voltage
33 MHz 6 3.3 V, 5 V
66 MHz 2 3.3 V
PCI-X
Frequency Maximum Slots Voltage
66 MHz 4 3.3 V
100 MHz 2 3.3 V
133 MHz 1 3.3 V