Intel Xeon X3440 BX80605X3440 User Manual
Product codes
BX80605X3440
Document Number: 424077 Revision: 2.0Thermal/Mechanical Specifications and Design Guidelines
49
Thermal Specifications
commands that are commonly implemented include Ping() , GetDIB() and 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
the processor-specific value stored in the static variable, T
CONTROL
. When the DTS
temperature data is less than T
CONTROL
, the fan speed control algorithm can reduce the
speed of the thermal solution fan. This remains the same as with the previous guidance
for fan speed control. Refer to
for fan speed control. Refer to
for guidance where the DTS temperature
data exceeds T
CONTROL
.
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 PROCHOT#. Therefore,
as the temperature approaches TCC activation, the value approaches zero degrees.
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 PROCHOT#. 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.
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.
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.
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.
Table 6-6.
Supported PECI Command Functions and Codes
Command Function
Supported on the
processor
Note
Ping()
Yes
GetDIB()
Yes
GetTemp()
Yes
Figure 6-5. Temperature Sensor Data Format
MSB
Upper nibble
Upper nibble
MSB
Lower nibble
Lower nibble
LSB
Upper nibble
Upper nibble
LSB
Lower nibble
Lower nibble
S
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Sign
Integer Value (0-511)
Fractional Value (~0.016)