Intel BX80571E5300 - Pentium 2.6 GHz Processor, Datasheet

Page: 83 / 100

Datasheet 83
Thermal Specifications and Design Considerations
5.3.2.3 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 where the PECI is know to be unresponsive.
Prior to a power-on RESET# and during RESET# assertion, PECI is not assured 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 damage. It is recommended that the PECI host controller take appropriate
action to protect the client processor device if valid temperature readings have not
been obtained in response to three consecutive GetTemp()s or for a one second time
interval. The host controller may also implement an alert to software in the event of a
critical or continuous fault condition.
5.3.2.4 PECI GetTemp0() Error Code Support
The error codes supported for the processor GetTemp() command are listed in
Table 27 :
§ §
Table 27. GetTemp0() Error Codes
Error Code Description
8000h General sensor error
8002h
Sensor is operational, but has detected a temperature below its operational
range (underflow)