Peci Specifications; Conceptual Fan Control Diagram For A Peci-Based Platform - Intel E5310 - Xeon 1.6 GHz 8M L2 Cache 1066MHz FSB LGA771 Active Quad-Core Processor Datasheet

Thermal Specifications
Figure 6-6.

Conceptual Fan Control Diagram For A PECI-Based Platform

Fan Speed Fan Speed
(RPM) (RPM)
6.3.1.2 Processor Thermal Data Sample Rate and Filtering
The DTS provides an improved capability to monitor device hot spots, which inherently
leads to more varying temperature readings over short time intervals. The DTS sample
interval range can be modified, and a data filtering algorithm can be activated to help
moderate this. The DTS sample interval range is 82 ms (default) to 20 ms (max). This
value can be set in BIOS.
To reduce the sample rate requirements on PECI and improve thermal data stability vs.
time the processor DTS also implements an averaging algorithm that filters the
incoming data. This is an alpha-beta filter with coefficients of 0.5, and is expressed
mathematically as: Current_filtered_temp = (Previous_filtered_temp / 2) +
(new_sensor_temp / 2). This filtering algorithm is fixed and cannot be changed. It is on
by default and can be turned off in BIOS.
Host controllers should utilize the min/max sample times to determine the appropriate
sample rate based on the controller's fan control algorithm and targeted response rate.
The key items to take into account when settling on a fan control algorithm are the DTS
sample rate, whether the temperature filter is enabled, how often the PECI host will
poll the processor for temperature data, and the rate at which fan speed is changed.
Depending on the designer's specific requirements the DTS sample rate and alpha-beta
filter may have no effect on the fan control algorithm.
6.3.2

PECI Specifications

6.3.2.1 PECI Device Address
The PECI device address for socket 0 is 0x30 and socket 1 is 0x31. Please note that
each address also supports two domains (Domain 0 and Domain 1).
6.3.2.2 PECI Fault Handling Requirements
PECI is largely a fault tolerant interface, including noise immunity and error checking
improvements over other compatible industry standard interfaces. The PECI client is as
reliable as the device that it is embedded within, and thus given operating conditions
Quad-Core Intel® Xeon® Processor 5300 Series Datasheet
Min Min
PECI = -20 PECI = -20
Temperature Temperature
(not intended to depict actual implementation) (not intended to depict actual implementation)
T T TCC Activation TCC Activation
CONTROL CONTROL
Setting Setting Temperature Temperature
Max Max
PECI = 0 PECI = 0
PECI = -10 PECI = -10
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