Intel BX80601920 Data Sheet - Page 80

Thermal Specifications

80

Datasheet

6.3.1.1

Fan Speed Control with Digital Thermal Sensor

Fan speed control solutions use a value stored in the static variable, T

CONTROL

. The DTS

temperature data, which is delivered over PECI (in response to a GetTemp0()

command), is compared to this T

CONTROL

reference. The DTS temperature is reported

as a relative value versus an absolute value. The temperature 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.

6.3.1.2

Processor Thermal Data Sample Rate and Filtering

The processor digital thermal sensor (DTS) provides an improved capability to monitor

device hot spots, which inherently leads to more varying temperature readings over

short time intervals. To reduce the sample rate requirements on PECI and improve

thermal data stability versus. time the processor DTS implements an averaging

algorithm that filters the incoming data. This filter is expressed mathematically as:

PECI(t) = PECI(t–1)+1/(2^^X)*[Temp – PECI(t–1)]

Where: PECI(t) is the new averaged temperature; PECI(t-1) is the previous

averaged temperature; Temp is the raw temperature data from the DTS; X is the

Thermal Averaging Constant (TAC)

Note:

Only values read using the PECI interface are averaged. Temperature values read using

the IA32_THERM_STATUS MSR are not averaged.

The Thermal Averaging Constant is a BIOS configurable value that determines the time

in milliseconds over which the DTS temperature values are averaged. Short averaging

times will make the averaged temperature values respond more quickly to DTS

changes. Long averaging times will result in better overall thermal smoothing but also

incur a larger time lag between fast DST temperature changes and the value read using

PECI. Refer to the appropriate processor Thermal and Mechanical Design Guidelines

(see

Section 1.2

) for further details on the Data Filter and the Thermal Averaging

Constant.

Within the processor, the DTS converts an analog signal into a digital value

representing the temperature relative to TCC activation. The conversions are in

integers with each single number change corresponding to approximately 1 °C. DTS

values reported using the internal processor MSR will be in whole integers.

As a result of the averaging function described above, DTS values reported over PECI

will include a 6-bit fractional value. Under typical operating conditions, where the

temperature is close to T

CONTROL

, the fractional values may not be of interest. But when

the temperature approaches zero, the fractional values can be used to detect the

activation of the TCC. An averaged temperature value between 0 and 1 can only occur

if the TCC has been activated during the averaging window. As TCC activation time

increases, the fractional value will approach zero. Fan control circuits can detect this

situation and take appropriate action as determined by the system designers. Of

course, fan control chips can also monitor the PROCHOT# pin to detect TCC activation

using a dedicated input pin on the package. Further details on how the Thermal

Averaging Constant influences the fractional temperature values are available in the

Thermal Design Guide.

Section	Page
Contents	3
Figures	4
Tables	5
Intel® Core™ i7-900 Desktop Processor Extreme Edition Series and Intel® Core™ i7-900 Desktop Processor Series Features	7
Revision History	8
1 Introduction	9
1.1 Terminology	10
1.2 References	11
2 Electrical Specifications	13
2.1 Intel® QPI Differential Signaling	13
2.2 Power and Ground Lands	13
2.3 Decoupling Guidelines	13
2.3.1 VCC, VTTA, VTTD, VDDQ Decoupling	14
2.4 Processor Clocking (BCLK_DP, BCLK_DN)	14
2.4.1 PLL Power Supply	14
2.5 Voltage Identification (VID)	14
2.6 Reserved or Unused Signals	17
2.7 Signal Groups	18
2.8 Test Access Port (TAP) Connection	19
2.9 Platform Environmental Control Interface (PECI) DC Specifications	20
2.9.1 DC Characteristics	20
2.9.2 Input Device Hysteresis	21
2.10 Absolute Maximum and Minimum Ratings	21
2.11 Processor DC Specifications	22
2.11.1 DC Voltage and Current Specification	23
2.11.2 VCC Overshoot Specification	29
2.11.3 Die Voltage Validation	30
3 Package Mechanical Specifications	31
3.1 Package Mechanical Drawing	31
3.2 Processor Component Keep-Out Zones	34
3.3 Package Loading Specifications	34
3.4 Package Handling Guidelines	34
3.5 Package Insertion Specifications	34
3.6 Processor Mass Specification	35
3.7 Processor Materials	35
3.8 Processor Markings	35
3.9 Processor Land Coordinates	36
4 Land Listing	37
5 Signal Descriptions	67
6 Thermal Specifications	71
6.1 Package Thermal Specifications	71
6.1.1 Thermal Specifications	71
6.1.2 Thermal Metrology	75
6.2 Processor Thermal Features	76
6.2.1 Processor Temperature	76
6.2.2 Adaptive Thermal Monitor	76
6.2.3 THERMTRIP# Signal	79
6.3 Platform Environment Control Interface (PECI)	79
6.3.1 Introduction	79
6.3.2 PECI Specifications	81
6.4 Storage Conditions Specifications	82
7 Features	83
7.1 Power-On Configuration (POC)	83
7.2 Clock Control and Low Power States	83
7.2.1 Thread and Core Power State Descriptions	84
7.2.2 Package Power State Descriptions	85
7.3 Sleep States	86
7.4 ACPI P-States (Intel® Turbo Boost Technology)	86
7.5 Enhanced Intel® SpeedStep® Technology	87
8 Boxed Processor Specifications	89
8.1 Introduction	89
8.2 Mechanical Specifications	90
8.2.1 Boxed Processor Cooling Solution Dimensions	90
8.2.2 Boxed Processor Fan Heatsink Weight	92
8.2.3 Boxed Processor Retention Mechanism and Heatsink Attach Clip Assembly	92
8.3 Electrical Requirements	92
8.3.1 Fan Heatsink Power Supply	92
8.4 Thermal Specifications	93
8.4.1 Boxed Processor Cooling Requirements	93

Intel BX80601920 Data Sheet - Page 80

Fan Speed Control with Digital Thermal Sensor, 3.1.2, Processor Thermal Data Sample Rate

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