Signal Description
Table 2-22. LOCK Transaction Handling
End Point
Source
PCI
PCI Express*
SHPC Memory
I/OxAPIC
Ignore2
Ignore2
N/A
Error Reported1
Error Reported1
N/A
CSR Memory
PCI
N/A
Forward to PCI with PxLOCK#
N/A
PCI Express*
Ignore2
NOTES:
1. For locked reads, a response of UR-EC is reported on the PCI Express* bus.
2. The transaction is treated as if it were a normal read or write transaction.
2.12
Hot Plug Controllers
The Intel® 6700PXH 64-bit PCI Hub hot plug controller allows PCI card removal, replacement,
and addition without powering down the system. The controller is compatible with the PCI
Standard Hot-Plug Controller and Subsystem Specification, Revision 1.0. The specification
includes two new register sets that are defined for the SHPC Capabilities List and the SHPC
Working Register Set. The new registers are defined as a PCI-PCI bridge capability in the
Intel® 6700PXH 64-bit PCI Hub and not as a separate PCI controller device. The new
specification also fixes the architectural proximity of the SHPC function to the PCI slots it controls.
The Intel® 6700PXH 64-bit PCI Hub may only control slots on its secondary bus(es) and there
must be a separate SHPC function associated with each of the logical PCI-PCI bridge configuration
spaces. The Standard Hot-Plug Controller in the Intel® 6700PXH 64-bit PCI Hub can control a
maximum of 6 slots in the system. It supports three to six PCI slots through an input/output serial
interface when operating in Serial Mode, and 1 to 2 slots through an input/output parallel interface
when operating in Parallel Mode. The input serial interface is polling and is in continuous
operation. The output serial interface is “demand” and acts only when requested. These serial
interfaces run at about 8.25 MHz regardless of the speed of the PCI bus. In parallel mode, the
Intel® 6700PXH 64-bit PCI Hub performs the serial to parallel conversion internally, so the serial
interface cannot be observed. However, internally the hot plug controller always operates in a serial
mode.
2.12.1
Mode Determination
The standard hot plug controller is enabled and the mode selected through pin strappings that are
sampled on the rising edge of PWROK signal. Table 2-23 shows the information. When the
standard hot plug controller is disabled (HPx_SLOT[3] = “0”), the standard hot plug capability
registers and the working register set are hidden from software and the standard hot plug controller
is essentially disabled. The number of standard hot plug slots the controller handles is logged into
the slot configuration register at offset 0Ch in the SHPC working register set. This register is a
read-only register and cannot be written to by BIOS to change the mode of operation of the
controller in the Intel® 6700PXH 64-bit PCI Hub (between serial and parallel).
Intel® 6700PXH 64-bit PCI Hub Datasheet
47
INTEL [ INTEL ]
