Thermal Specifications
Intel
®
Xeon
®
Processor C5500/C3500 Series and LGA1366 Socket
Thermal/Mechanical Design Guide
August 2010
53
Order Number: 323107-002US
6.3.2
PECI Specifications
6.3.2.1
PECI Device Address
The processor PECI_ID# signal is used to configure the PECI address for the given
processor. The PECI register resides at:
• Address 30h when PECI_ID# is pulled to Vtt.
• Address 31h when PECI_ID# is terminated to ground.
6.3.2.2
PECI Command Support
PECI commands are in the
Intel
®
Xeon
®
Processor C5500/C3500 Series
Datasheet)
.
6.3.2.3
PECI Fault Handling Requirements
PECI is largely a fault tolerant interface, including noise immunity and error checking
improvements over other comparable industry standard interfaces. The PECI client is
as reliable as the device that it is embedded in, and thus given operating conditions
that fall under the specification, the PECI will always respond to requests and the
protocol itself can be relied upon to detect any transmission failures. There are,
however, certain scenarios in which the PECI is know to be unresponsive. Before a
power on RESET# and during RESET# assertion, PECI is not ensured to provide reliable
thermal data. System designs should implement a default power-on condition that
ensures proper processor operation during the time frame when reliable data is not
available via PECI.
To protect platforms from potential operational or safety issues due to an abnormal
condition on PECI, the Host controller should take action to protect the system from
possible damaging states. If the Host controller cannot complete a valid PECI
transactions of GetTemp0() with a given PECI device over three consecutive failed
transactions or a one second max specified interval, then it should take appropriate
actions to protect the corresponding device and/or other system components from
overheating. The host controller may also implement an alert to software in the event
of a critical or continuous fault condition.
6.3.2.4
PECI GetTemp0() Error Code Support
The error codes supported for the processor GetTemp() command are listed in
.
§
Table 6-15. GetTemp0() Error Codes
Error Code
Description
8000h
General sensor error