Signal Description
2.18.2.5
Hot Plug Reset
This reset is initiated by a write to the hot plug command register with the change frequency
command. Note that a write to this register might do any of the following:
• Change the frequency (33/66/100/133 MHz).
• Change the mode (PCI or PCI-X).
• Change nothing but rewrite the present settings.
Any write (doing any of the three above) will cause a reset of the particular PCI segment to reset.
This reset is asynchronous by nature to the PCI clock as the hot plug logic runs off of an internal
clock that ‘may’ be asynchronous to the PCI clock. This reset will cause the any newly written
frequency or PCI mode information to take effect. The Intel® 6702PXH 64-bit PCI Hub will
support all changes in mode because of hot plug events including switching from PCI to PCI-X
protocols or changing the frequency.
2.19
Reliability, Availability, and Serviceability (RAS)
The Intel® 6702PXH 64-bit PCI Hub provides the RAS features listed below to serve the needs of
enterprise class servers and telecommunication blade applications.
2.19.1
PCI Express Error Handling
The PCI Express link in the Intel® 6702PXH 64-bit PCI Hub is 32-bit CRC protected providing
for very high reliability. With a target bit error rate of 10-12 the 32-bit CRC combined with the
8b/10b encoding on the serial link, provides for greater than 10 years in MTBF (mean time
between failure). The smaller link packets will utilize a 16-bit CRC scheme. PCI Express also
provides for a software-transparent recovery from temporary link failures. When received packets
are in error, hardware could automatically retransmit the packet. In case of permanent link failure,
the link can reconfigure itself for a narrower width and for a lower performance operation. The
Intel® 6702PXH 64-bit PCI Hub supports this downgraded operation from x8 to x4.
2.19.2
2.19.3
PCI Error Protection
PCI buses are parity protected. Upper and lower 32 bits on the PCI bus are separately parity
protected.
PCI Standard Hot Plug Controller
The Intel® 6702PXH 64-bit PCI Hub supports the PCI Standard Hot-Plug Controller and
Subsystem Specification, Revision 1.0, which allows PCI cards to be hot added or removed without
bringing down the system.
2.19.4
SMBus
The Intel® 6702PXH 64-bit PCI Hub supports full access to the Intel® 6702PXH 64-bit PCI Hub
configuration and memory space from the SMBus for system debug and management.
Intel® 6702PXH 64-bit PCI Hub Datasheet
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