Temperature Sensor Data Format; Supported Peci Command Functions And Codes - Intel BX80605X3440 - Quad Core Xeon X3440 Reference

Thermal Specifications
commands that are commonly implemented include Ping() , GetDIB() and GetTemp().
Table 6-6.

Supported PECI Command Functions and Codes

Command Function
Ping()
GetDIB()
GetTemp()
Note:
1. Thermal management related commands supported by the processor. Common command that will be
implemented for system design.
6.3.2 PECI Client Capabilities
The processor PECI clients are designed to support processor thermal management.
Processor fan speed control is managed by comparing DTS temperature data against
the processor-specific value stored in the static variable, T
temperature data is less than T
speed of the thermal solution fan. This remains the same as with th e previous guidance
for fan speed control. Refer to
data exceeds T
The DTS temperature data is delivered over PECI, in response to a GetTemp()
command, and reported as a relative value to TCC activation target. The temperature
data reported over PECI is always a negative value and represents a delta below the
onset of thermal control circuit (TCC) activation, as indicated by PROCHO T#. Therefore,
as the temperature approaches TCC activation, the value approaches zero degrees.
6.3.3 Temperature Data
6.3.3.1 Format
The temperature is formatted in a 16-bit, 2's complement value representing a number
of 1/64 degrees centigrade. This format allows temperatures in a range of ±512 °C to
be reported to approximately a 0.016 °C resolution.
Figure 6-5.

Temperature Sensor Data Format

MSB
Upper nibble
S x x x
Sign
6.3.3.2 Interpretation
The resolution of the processor's Digital Thermal Sensor (DTS) is approximately 1 °C.
PECI temperatures are sent through a configurable low-pass filter prior to delivery in
the GetTemp() response data. The output of this filter produces temperatures at the full
1/64 °C resolution even though the DTS itself is not this accurate.
Document Number: 424077 Revision: 2.0Thermal/Mechanical Specifications and Design Guidelines
CONTROL
Section 6.1.3
.
CONTROL
MSB
Lower nibble
x x x x
Integer Value (0-511)
Supported on the
processor
Yes
Yes
Yes
CONTROL
, the fan speed control algorithm can reduce the
for guidance where the DTS temperature
LSB
Upper nibble
x x x x
Fractional Value (~0.016)
Note
1
1
1
. When the DTS
LSB
Lower nibble
x x x x
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