Intel 521 Data Sheet - Page 96

96

Datasheet

Boxed Processor Specifications

If the boxed processor fan heatsink 4-pin connector is connected to a 4-pin motherboard header and

the motherboard is designed with a fan speed controller with PWM output (CONTROL see

Table 7-1

) and remote thermal diode measurement capability the boxed processor will operate as

follows:

As processor power has increased the required thermal solutions have generated increasingly more

noise. Intel has added an option to the boxed processor that allows system integrators to have a

quieter system in the most common usage.

The 4th wire PWM solution provides better control over chassis acoustics. This is achieved by

more accurate measurement of processor die temperature through the processor's temperature

diode (T

diode

). Fan RPM is modulated through the use of an ASIC located on the motherboard that

sends out a PWM control signal to the 4th pin of the connector labeled as CONTROL. The fan

speed is based on actual processor temperature instead of internal ambient chassis temperatures.

If the new 4-pin active fan heat sink solution is connected to an older 3-pin baseboard processor fan

header, it will default back to a thermistor controlled mode, allowing compatibility with existing 3-

pin baseboard designs. Under thermistor controlled mode, the fan RPM is automatically varied

based on the Tinlet temperature measured by a thermistor located at the fan inlet.

For more details on specific motherboard requirements for 4-wire based fan speed control see the

Intel

®

Pentium

®

4 Processor on 90 nm Process in the 775-Land Package Thermal Design Guide

.

§

Table 7-2. Fan Heatsink Power and Signal Specifications

Boxed Processor Fan

Heatsink Set Point (

º

C)

Boxed Processor Fan Speed

Notes

X

≤

30

When the internal chassis temperature is below or equal to this set point,

the fan operates at its lowest speed. Recommended maximum internal

chassis temperature for nominal operating environment.

1

NOTES:

1.

Set point variance is approximately ± 1 °C from fan heatsink to fan heatsink.

Y = 34

When the internal chassis temperature is at this point, the fan operates

between its lowest and highest speeds. Recommended maximum

internal chassis temperature for worst-case operating environment.

-

Z

≥

38

When the internal chassis temperature is above or equal to this set point,

the fan operates at its highest speed.

-

Section	Page
Contents	3
Revision History	7
Intel® Pentium® 4 Processors 570/571, 560/561, 550/551, 540/541, 530/531, and 520/521	9
1 Introduction	11
1.1 Terminology	12
1.1.1 Processor Packaging Terminology	12
1.2 References	13
2 Electrical Specifications	15
2.1 FSB and GTLREF	15
2.2 Power and Ground Lands	15
2.3 Decoupling Guidelines	15
2.3.1 VCC Decoupling	16
2.3.2 FSB GTL+ Decoupling	16
2.3.3 FSB Clock (BCLK[1:0]) and Processor Clocking	16
2.4 Voltage Identification	17
2.4.1 Phase Lock Loop (PLL) Power and Filter	19
2.5 Reserved, Unused, FC and TESTHI Signals	20
2.6 FSB Signal Groups	21
2.7 GTL+ Asynchronous Signals	22
2.8 Test Access Port (TAP) Connection	23
2.9 FSB Frequency Select Signals (BSEL[2:0])	23
2.10 Absolute Maximum and Minimum Ratings	24
2.11 Processor DC Specifications	24
2.12 VCC Overshoot Specification	33
2.12.1 Die Voltage Validation	33
2.13 GTL+ FSB Specifications	34
3 Package Mechanical Specifications	35
3.1 Package Mechanical Drawing	35
3.2 Processor Component Keep-Out Zones	39
3.3 Package Loading Specifications	39
3.4 Package Handling Guidelines	39
3.5 Package Insertion Specifications	40
3.6 Processor Mass Specification	40
3.7 Processor Materials	40
3.8 Processor Markings	40
3.9 Processor Land Coordinates	41
4 Land Listing and Signal Descriptions	43
4.1 Processor Land Assignments	43
4.2 Alphabetical Signals Reference	66
5 Thermal Specifications and Design Considerations	75
5.1 Processor Thermal Specifications	75
5.1.1 Thermal Specifications	75
5.1.2 Thermal Metrology	79
5.2 Processor Thermal Features	79
5.2.1 Thermal Monitor	79
5.2.2 Thermal Monitor 2	80
5.2.3 On-Demand Mode	81
5.2.4 PROCHOT# Signal	82
5.2.5 THERMTRIP# Signal	82
5.2.6 TCONTROL and Fan Speed Reduction	82
5.2.7 Thermal Diode	83
6 Features	85
6.1 Power-On Configuration Options	85
6.2 Clock Control and Low Power States	85
6.2.1 Normal State	86
6.2.2 HALT and Enhanced HALT Powerdown States	86
6.2.2.1 HALT Powerdown State	86
6.2.2.2 Enhanced HALT Powerdown State	86
6.2.3 Stop-Grant State	87
6.2.4 Enhanced HALT Snoop or HALT Snoop State, Grant Snoop State	88
6.2.4.1 HALT Snoop State, Grant Snoop State	88
6.2.4.2 Enhanced HALT Snoop State	88
7 Boxed Processor Specifications	89
7.1 Mechanical Specifications	90
7.1.1 Boxed Processor Cooling Solution Dimensions	90
7.1.2 Boxed Processor Fan Heatsink Weight	91
7.1.3 Boxed Processor Retention Mechanism and Heatsink Attach Clip Assembly	91
7.2 Electrical Requirements	91
7.2.1 Fan Heatsink Power Supply	91
7.3 Thermal Specifications	93
7.3.1 Boxed Processor Cooling Requirements	93

Intel 521 Data Sheet - Page 96

Table 7-2. Fan Heatsink Power and Signal Specifications

Page 96 highlights