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

Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide 127
Intel
®
82870P2 (P64H2)
8.2.5 Disabling/Enabling an Intel
®
P64H2 Hot-Plug Controller
8.2.5.1 Hot-Plug Strapping Options
The HPx_SLOT [2:0] strapping pins are used to enable and disable the Hot-Plug controller.
Table 8-15 lists the strapping options associated with these pins, and the modes of operation they
enable.
NOTES:
1. Refer to Section 8.2.6 for single-slot parallel mode operation.
2. Refer to Section 8.2.7 for dual-slot parallel mode operation.
3. Refer to Section 8.2.7.9 for serial mode operation.
8.2.5.2 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.
8.2.6 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.
8.2.6.1 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 HxSWITCH signal can be used to control the
isolation switches.
8.2.6.2 PCI Clock
In single-slot parallel mode, it is expected that PxPCLK0 is used.
Table 8-15. Hot-Plug Mode
HPx_SLOT 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