Intel Xeon User Manual

Design Guide 103
Intel
®
82870P2 (P64H2)
8.2.4 Disabling/Enabling an Intel
®
P64H2 Hot Plug Controller
8.2.4.1 Hot Plug Strapping Options
The HPxSLOT [2:0] strapping pins are used to enable and disable the Hot Plug Controller.
Table 8-8 lists the strapping options associated with these pins, and the modes of operation they
enable.
NOTES:
1. Refer to Section 8.2.5 for Single Slot Parallel Mode Operation.
2. Refer to Section 8.2.6 for Dual Slot Parallel Mode Operation.
3. Refer to Section 8.2.6.9 for Serial Mode Operation.
8.2.4.2 Hot Plug Registers’ Visibility
The Hot Plug controller function is completely hidden when the controller is disabled by the slot
strapping pins HPx_SLOT[2:0], and the registers are not available or accessible.
8.2.5 Single Slot Parallel Mode
Single Slot Parallel Mode allows for only one card to be connected to the PCI/PCI-X Bus. This
mode should be used only to implement a one-slot Hot Plug solution because of the behavior of the
PCI bus when in this mode. No serialization/deserialization logic is required for this mode of
operation.
8.2.5.1 Required Additional Logic
Single Slot Parallel Mode requires a power switch to be used to turn the slot power on and off.
Single Slot Parallel Mode does not require the use of a bus and clock switch. In this mode, all PCI
signals are driven to ground whenever a PCI card is to be disconnected.
If the platform supports PME# or SMBus connections to the slot, isolation logic is required to
disconnect these signals prior to inserting or removing a card. See the PCI Hot Plug Specification,
Revision 1.1 for implementation details. The Hx_SWITCH signal can be used to control the
isolation switches.
8.2.5.2 PCI Clock
In Single Slot Parallel Mode, it is expected that PxPCLK [0] is used.
Table 8-8. Hot Plug Mode
HPxSLOT [2:0] Hot Plug Mode Notes
000 Hot Plug Disabled
001 1-Slot (Parallel Mode) 1
010 2-Slot (Parallel Mode) 2
011 3-Slot (Serial Mode) 3
100 4-Slot (Serial Mode) 3
101 5-Slot (Serial Mode) 3
110 6-Slot (Serial Mode) 3
111 Reserved

Intel Xeon Specifications

General

Brand	Intel
Model	Xeon
Category	Processor
Language	English