On 90 nm Process in 775-land LGA Package and
supporting Intel
May 2005
®
Extended Memory 64 Technology
Φ
Document Number: 302351-004
Contents
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future definition and shall have no responsibility whatsoever for conflict s or inco mpatibilities arising from future changes to them.
®
The Intel
the product to deviate from published specifications. Current characterized errata are available on request.
∆
different processor families.
1
Technology enabled chipset, BIOS and operating system. Performance will vary depending on the specific hardware and software you use. See http:/
/www.intel.com/info/hyperthreading/ for more information including details on which processors support HT Technology.
ΦIntel
drivers and applications enabled for Intel EM64T. Processor will not operate (including 32-bit operation) without an Intel EM64T-enabled BIOS.
Performance will vary depending on your hardware and software configurations. See http://www.intel.com/info/em64t for more information including
details on which processors support EM64T or consult with your system vendor for more information.
Enabling Execute Disable Bit functionality requires a PC with a processor with Execute Disable Bit capability and a support ing operating system.
Check with your PC manufacturer on whether your system delivers Execute Disable Bit functionality.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Intel, Pentium, Itanium, Intel Xeon, Intel NetBurst and the Intel logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in
(HT Technology) for all frequencies with
800 MHz front side bus (FSB)
®
• Intel
Pentium® 4 processors 571, 561, 551, 541,
531, and 521 support Intel
Technology (EM64T)
®
Extended Memory 64
Φ
1
• Supports Execute Disable Bit capability
• Binary compatible with applications run ning on
previous members of the Intel microprocessor line
• Intel NetBurst
®
microarchitecture
• FSB frequency at 800 MHz
• Hyper-Pipelined Technology
• Advance Dynamic Execution
• Very deep out-of-order execution
• Enhanced branch prediction
• 16-KB Level 1 data cache
• 1-MB Advanced Transfer Cache (on-die, full-
speed Level 2 (L2) cache) with 8-way associativity
and Error Correcting Code (ECC)
• 144 Streaming SIMD Extensions 2 (SSE2)
instructions
• 13 Streaming SIMD Extensions 3 (SSE3)
instructions
• Enhanced floating point and multimedia unit for
enhanced video, audio, encryption, and 3D
performance
• Power Management capabilities
• System Management mode
• Multiple low-power states
• 8-way cache associativity provides improved
cache hit rate on load/store operations
• 775-land Package
• Optimized for 32-bit applications running on
advanced 32-bit operating systems
The Intel® Pentium® 4 processor family supporting Hyper-Threading Technology1 (HT Technology) delivers
Intel's advanced, powerful processors for desktop PCs and entry-level workstations that are based on the Intel
NetBurst
usages where end-users can truly appreciate and experience the performance. These applications include Internet
audio and streaming video, image processing, video content creation, speech, 3D, CAD, games, multimedia, and
multitasking user environments. Intel
execute operating systems and applications written to take advange of the Intel EM64T
®
microarchitecture. The Pentium 4 processor is designed to deliver performance across applications and
®
Extended Memory 64 Technology enables the Intel® Pentium® processor to
Φ
.
§
Datasheet9
Contents
10Datasheet
1Introduction
Introduction
The Intel® Pentium® 4 processor on 90 nm process in the 775-land package is a follow on to the
Pentium 4 processor in the 478-pin package with enhancements to the Intel NetBurst
microarchitecture. The Pentium 4 processor on 90 nm process in the 775-land package uses FlipChip Land Grid Array (FC-LGA4) package technology, and plugs into a 775LGA socket. The
Pentium 4 processor in the 775-land package, like its predecessor, the Pentium 4 processor in the
478-pin package, is based on the same Intel 32-bit microarchitecture and maintains the tradition of
compatibility with IA-32 software.
Note:In this document the Pentium 4 processor on 90 nm process in the 775-land package is also referred
to as the processor.
The Pentium 4 processor on 90 nm process in the 775-land package supports Hyper-Threading
Technology
logical processors. While some execution resources (such as caches, execution units, and buses)
are shared, each logical processor has its own architecture state with its own set of general-purpose
registers, control registers to provide increased system responsiveness in multitasking
environments, and headroom for next generation multithreaded applications. Intel recommends
enabling Hyper-Threading Technology with Microsoft Windows* XP Professional or
Windows* XP Home, and disabling Hyper-Threading Technology via the BIOS for all previous
versions of Windows operating systems. For more information on Hyper-Threading Technology,
see http://www.intel.com/info/hyperthreading. Refer to Section 6.1, for Hyper-Threading
T echnology configuration details.
The Intel Pentium 4 processor 571, 561, 541, 531, and 521 su pport Intel
T echnology (EM64T)
the processor to execute operating systems and applications written to take advantage of Intel
EM64T. With appropriate 64 bit supporting hardware and software, platforms based on an Intel
processor supporting Intel
Further details on the 64-bit extension architecture and programming model is provided in th e
Intel
technology/64bitextensions/.
1
. Hyper-Threading Technology allows a single, physical processor to function as two
®
Φ
as an enhancement to Intel’ s IA-32 architecture. This enhancement enables
®
EM64T can enable use of extended virtual and physical memory.
In addition to supporting all the existing Streaming SIMD Extensions 2 (SSE2), there are 13 new
instructions that further extend the capabilities of Intel processor technology. These new
instructions are called Streaming SIMD Extensions 3 (SSE3). These new instructions enhance the
performance of optimized applications for the digital home such as video, image processing, and
media compression technology. 3D graphics and other entertainment applications such as gaming
will have the opportunity to take advantage of these new instructions as platforms with the Pentium
4 processor in the 775-land package and SSE3 become available in the market place.
The processor’s Intel NetBurst microarchitecture FSB uses a split-transaction, deferred reply
protocol like the Pentium 4 processor. The Intel NetBurst microarchitecture FSB uses SourceSynchronous Transfer (SST) of address and data to improve performance by transferring data four
times per bus clock (4X data transfer rate, as in AGP 4X). Along with the 4X data bus, the address
bus can deliver addresses two times per bus clock and is referred to as a "double-clocked" or 2X
address bus. Working together, the 4X data bus and 2X address bus provide a data bus bandwidth
of up to 6.4 GB/s.
Datasheet11
Introduction
The Pentium 4 processor on 90 nm process in the LGA775-land package will also include the
Execute Disable Bit capability previously available in Intel
combined with a support operating system allows memory to be marked as executable or nonexecutable. If code attempts to run in non-executable memory the processor raises an error to the
operating system. This feature can prevent some classes of viruses or worms that exploit buffer
overrun vulnerabilities and can thus help improve the overall security of the system. See the IntelArchitecture Software Developer's Manual for more detailed information.
Intel will enable support components for the processor including heatsink, heatsink retention
mechanism, and socket. Manufacturability is a high priority; hence, mechanical assembly may be
completed from the top of the baseboard and should not require any special tooling.
The processor includes an address bus powerdown capability that removes power from the address
and data pins when the FSB is not in use. This feature is always enabled on the processor.
1.1Terminology
A ‘#’ symbol after a signal name refers to an active low signal, indicating a signal is in the active
state when driven to a low level. For example, when RESET# is low, a reset has been requested.
Conversely, when NMI is high, a nonmaskable interrupt has occurred. In the case of signals where
the name does not imply an active state but describes part of a binary sequence (such as address or
data), the ‘#’ symbol implies that the signal is inverted. For example, D[3:0] = ‘HLHL’ refers to a
hex ‘A’, and D[3:0]# = ‘LHLH’ also refers to a hex ‘A’ (H= High logic level, L= Low logic level).
“FSB” refers to the interface between the processor and system core logic (a.k.a. the chipset
components). The FSB is a multiprocessing interface to processors, memory, and I/O.
®
Itanium® processors. This feature
®
1.1.1Processor Packaging Terminology
Commonly used terms are explained here for clarification:
• Pentium 4 processor on 90 nm process in the 775-land package — Processor in the FC-
LGA4 package with a 1-MB L2 cache.
• Processor — For this document, the term processor is the generic form of the Pentium 4
processor in the 775-land package.
• Keep-out zone — The area on or near the processor that system design can not use.
• Intel 925X/915G/915P Express chipsets — Chipsets that supports DDR and DDR2 memory
technology for the Pentium 4 processor in the 775-land package.
• Processor core — Processor core die with integrated L2 cache.
• FC-LGA4package — The Pentium 4 processor in the 775-land package is available in a Flip-
Chip Land Grid Array 4 package, consisting of a processor core mounted on a substrate with
an integrated heat spreader (IHS).
• LGA775 socket — The Pentium 4 processor in the 775-land package mates with the system
board through a surface mount, 775-land, LGA socket.
• Integrated heat spreader (IHS) —A component of the processor package used to enhance
the thermal performance of the package. Component thermal solutions interface with the
processor at the IHS surface.
12Datasheet
• Retention mechanism (RM)—Since the LGA775 socket does not include any mechanical
features for heatsink attach, a retention mechanism is required. Component thermal solutions
should attach to the processor via a retention mechanism that is independent of the socket.
• Storage conditions—Refers to a non-operational state. The processor may be installed in a
platform, in a tray, or loose. Processors may be sealed in packaging or exposed to free air.
Under these conditions, processor lands should not be connect ed to any supp ly voltages, have
any I/Os biased, or receive any clocks. Upon exposure to “free air” (i.e., unsealed packaging or
a device removed from packaging material) the processor must be handled in accordance with
moisture sensitivity labeling (MSL) as indicated on the packaging material.
• Functional operation—Refers to normal operating conditions in which all processor
specifications, including DC, AC, system bus, signal quality, mechanical and thermal, are
satisfied.
1.2References
Material and concepts available in the following documents may be beneficial when reading this
document.
Table 1-1. References
Introduction
Document
®
Intel
Pentium® 4 Processor on 90 nm Process Specification Update
®
Intel
Pentium® 4 Processor on 90 nm Process in the 775-Land Package
Thermal Design Guidelines
Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket
This chapter describes the electrical characteristics of the processor interfaces and signals. DC
electrical characteristics are provided.
2.1FSB and GTLREF
Most processor FSB signals use Gunning Transceiver Logic (GTL+) signaling technology.
Platforms implement a termination voltage level for GTL+ signals defined as V
provided via a separate voltage source and not be connected to V
improved noise tolerance as processor frequency increases. Because of the speed improvements to
the data and address bus, signal integrity and platform design methods have beco me m ore critical
than with previous processor families.
The GTL+ inputs require a reference voltage (GTLREF) that is used by the receivers to determine
if a signal is a logical 0 or a logical 1. GTLREF must be generated on the system board (see
Table 2-18 for GTLREF specifications). T ermination resistors are provided on the processor silicon
and are terminated to V
need to terminate the bus on the system board for most GTL+ signals.
. Intel chipsets will also provide on-die termination, thus eliminating the
TT
CC
Electrical Specifications
. VTT must be
. This configuration allows for
TT
Some G TL+ signals do not include on-die termination and must be terminated on the system board.
See Table 2-4 for details regarding these signals.
The GTL+ bus depends on incident wave switching. Therefore, timing calculations for GTL+
signals are based on flight time as opposed to capacitive deratings. Analog signal simulation of the
FSB, including trace lengths, is highly recommended when designing a system.
2.2Power and Ground Lands
For clean on-chip power distribution, the Pentium 4 processor in the 775-land package has
226 V
all V
plane. The processor V
IDentification (VID) signals.
(power), 24 VTT and 273 V
CC
lands must be connected to VTT, while all VSS lands must be connected to a system ground
TT
lands must be supplied the voltage determined by the Voltage
CC
(ground) lands. All power lands must be connected to VCC,
SS
2.3Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the processor is capable of
generating large current swings between low and full power states. This may cause voltages on
power planes to sag below their minimum values if bulk decoupling is not adequate. Care must be
taken in the board design to ensure that the voltage provided to the processor remains within the
specifications listed in Table 2-8. Failure to do so can result in timing violations or reduced lifetime
of the component. For further information and design guidelines, refer to th e Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket.
Datasheet15
Electrical Specifications
2.3.1VCC Decoupling
Regulator solutions need to provide bulk capacitance with a low Effective Series Resistance (ESR)
and keep a low interconnect resistance from the regulator to the socket. Bulk decoupling for the
large current swings when the part is powering on, or entering/exiting low power states, must be
provided by the voltage regulator solution (VR). For more details on this topic, refer to the Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket.
2.3.2FSB GTL+ Decoupling
The Pentium 4 processor in the 775-land package integrates signal termination on the die as well as
incorporating high frequency decoupling capacitance on the processor package. Decoupling must
also be provided by the system baseboard for proper GTL+ bus operation.
2.3.3FSB Clock (BCLK[1:0]) and Processor Clocking
BCLK[1:0] directly controls the FSB interface speed as well as the core frequency of the processor .
As in previous generation processors, the Pentium 4 processor in the 775-land package core
frequency is a multiple of the BCLK[1:0] frequency. The processor bus ratio multiplier will be set
at its default ratio during manufacturing. No user intervention is necessary, and the processor will
automatically run at the speed indicated on the package.
The Pentium 4 processor in the 775-land package uses a differential clocking implementation. For
more information on the Pentium 4 processor in the 775-land package clocking, refer to the
CK410/CK410M Clock Synthesizer/Driver Specification.
Table 2-1. Core Frequency to FSB Multiplier Configuration
Multiplication of System Core
Frequency to FSB Frequency
1.Individual processors operate only at or below the rated frequency.
2.Listed frequencies are not necessarily committed production frequencies.
Core Frequency (200 MHz
BCLK/800 MHz FSB)
Notes
1, 2
16Datasheet
2.4Voltage Identification
The VID specification for the Pentium 4 processor in the 775-land package is supported by the
Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket. The voltage set
by the VID signals is the reference VR output voltage to be delivered to the processor V
minimum voltage is provided in Table 2-8 and changes with frequency. This allows processors
running at a higher frequency to have a relaxed minimum voltage specification. The specifications
have been set such that one voltage regulator can work with all supported frequencies.
Individual processor VID values may be calibrated during manufacturing such that two devices at
the same speed may have different VID settings.
The Pentium 4 processor in the 775-land package uses six voltage identification signals, VID[5:0],
to support automatic selection of power supply voltages. Table 2-2 specifies the voltage level
corresponding to the state of VID[5:0]. A ‘1’ in this table refers to a high voltage level and a ‘0’
refers to low voltage level. I f the processor socket is empty (VID[5:0] = x11111), or the voltage
regulation circuit cannot supply the voltage that is requested, it must disable itself. See the Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket for more details.
Power source characteristics must be guaranteed to be stable when the supply to the voltage
regulator is stable.
Electrical Specifications
pins. A
CC
The LL_ID[1:0] lands are used by the platform to configure the proper loadline slope for the
processor. LL_ID[1:0] = 00 for the Pentium 4 processor in the 775-land package.
The VTT_SEL land is used by the platform to configure the proper V
voltage level for the
TT
processor. VTT_SEL = 1 for the Pentium 4 processor in the 775-land package.
The GTLREF_SEL signal is used by the platform to select the appropriate chipset GTLREF level.
GTLREF_SEL = 0 for the Pentium 4 processor in the 775-land package.
LL_ID[1:0] and VTT_SEL are signals that are implemented on the processor package. That is,
processor in the 775-land package. Since these PLLs are analog, they require low noise power
supplies for minimum jitter. Jitter is detrimental to the system: it degrades external I/O timings as
well as internal core timings (i.e., maximum frequency). To prevent this degradation, these supplies
must be low pass filtered from V
are power sources required by the PLL clock generators for the Pentium 4
.
TT
Electrical Specifications
The AC low-pass requirements, with input at V
• < 0.2 dB gain in pass band
• < 0.5 dB attenuation in pass band < 1 Hz
• > 34 dB attenuation from 1 MHz to 66 MHz
• > 28 dB attenuation from 66 MHz to core freq uency
The filter requirements are illustrated in Figure 2-1.
0.2 dB
0 dB
–0.5 dB
Forbidden
Zone
–28 dB
are as follows:
TT
Forbidden
Zone
–34 dB
1 MHz6 6 MHzfcorefpeak1 HzDC
Passband
NOTES:
1. Diagram not to scale.
2. No specification exists for frequencies beyond fcore (core frequency).
3. fpeak, if existent, should be less than 0.05 MHz.
Datasheet19
High
Frequency
Band
Filter_Spec
Electrical Specifications
2.5Reserved, Unused, FC and TESTHI Signals
All RESERVED signals must remain unconnected. Connection of these signals to VCC, VSS, V
or to any other signal (including each other) can result in component malfunction or
incompatibility with future processors. See Chapter 4 for a land listing of the processor and the
location of all RESERVED signals.
For reliable operation, always connect unused inputs or bidirectional signals to an appropriate
signal level. In a system level design, on-die termination has been included on the Pentium 4
processor in the 775-land package to allow signals to be terminated within the processor silicon.
Most unused GTL+ inputs should be left as no connects, as GTL+ termination is provided on the
processor silicon. However, see Table 2-4 for details on GTL+ signals that do not include on-die
termination. Unused active high inputs should be connected through a resistor to ground (V
Unused outputs can be left unconnected, however this may interfere with some test access port
(TAP) functions, complicate debug probing, and prevent boundary scan testing. A resistor must be
used when tying bidirectional signals to power or ground. When tying any signal to power or
ground, a resistor will also allow for system testability. For unused GTL+ input or I/O signals, use
pull-up resistors of the same value as the on-die termination resistors (R
more details.
TAP, GTL+ Asynchronous inputs, and GTL+ Asynchronous outputs do not include on-die
termination. Inputs and used outputs must be terminated on the system board. Unused outputs may
be terminated on the system board or left unconnected. Note that leaving unused outputs
unterminated may interfere with some TAP functions, complicate debug probing, and prevent
boundary scan testing.
FCx signals are signals that are available for compatibility with other processors.
The TESTHI signals must be tied to the processor V
resistor has a resistance value within ±20% of the impedance of the board transmission line traces.
For example, if the trace impedance is 60 Ω, then a value between 48 Ω and 72 Ω is required.
using a matched resistor, where a matched
TT
). Refer to Table 2-18 for
TT
SS
TT,
).
The TESTHI signals may use individual pull-up resistors or be grouped together as detailed below.
A matched resistor must be used for each group:
• TESTHI[1:0]
• TESTHI[7:2]
• TESTHI8 – cannot be grouped with other TESTHI signals
• TESTHI9 – cannot be grouped with other TESTHI signals
• TESTHI10 – cannot be grouped with other TESTHI signals
• TESTHI11 – cannot be grouped with other TESTHI signals
• TESTHI12 – cannot be grouped with other TESTHI signals
• TESTHI13 – cannot be grouped with other TESTHI signals
20Datasheet
2.6FSB Signal Groups
The FSB signals have been combined into groups by buffer type. GTL+ input signals have
differential input buffers, which use GTLREF as a reference level. In this document, the term
"GTL+ Input" refers to the GTL+ input group as well as the GTL+ I/O group when receiving.
Similarly, "GTL+ Output" refers to the GTL+ output group as well as the GTL+ I/O group when
driving.
With the implementation of a source synchronous data bus comes the need to specify two sets of
timing parameters. One set is for common clock signals which are dependent upon the rising edge
of BCLK0 (ADS#, HIT#, HITM#, etc.) and the second set is for the source synchronous signals
which are relative to their respective strobe lines (data and address) as well as the rising edge of
BCLK0. Asychronous signals are still present (A20M#, IGNNE#, etc.) and can become active at
any time during the clock cycle. Table 2-3 identifies which signals are common clock, source
synchronous, and asynchronous.
GTL+ Asynchronous Input/OutputPROCHOT#
TAP InputSynchronous to TCKTCK, TDI, TMS, TRST#
TAP OutputSynchronous to TCKTDO
FSB ClockClockBCLK[1:0], ITP_CLK[1:0]
2. In processor systems where there is no debug port implemented on the system board, these signals are used
to support a debug port interposer. In systems with the debug port implemented on the system board, these
signals are no connects.
3. The value of these signals during the active-to-inactive edge of RESET# defines the processor configuration
options. See Section 6.1 for details.
Legacy input signals such as A20M#, IGNNE#, INIT#, SMI#, and STPCLK# use CMOS input
buffers. All of these signals follow the same DC requirements as GTL+ signals, however the
outputs are not actively driven high (during a logical 0 to 1 transition) by the processor. These
signals do not have setup or hold time specifications in relation to BCLK[1:0].
All of the GTL+ Asynchronous signals are required to be asserted/de-asserted for at least six
BCLKs for the processor to recognize the proper signal state. See Section 6.2 for additional timing
requirements for entering and leaving the low power states.
22Datasheet
Electrical Specifications
2.8Test Access Port (TAP) Connection
Due to the voltage levels supported by other components in the Test Access Port (TAP) logic, it is
recommended that the Pentium 4 processor in the 775-land package be first in the TAP chain and
followed by any other components within the system. A translation buffer should be used to
connect to the rest of the chain unless one of the other components is capable of accepting an input
of the appropriate voltage level. Similar considerations must be made for TCK, TMS, TRST#, TDI,
and TDO. Two copies of each signal may be required, with each driving a different voltage level.
2.9FSB Frequency Select Signals (BSEL[2:0])
The BSEL[2:0] signals are used to select the frequency of the processor input clock (BCLK[1:0]).
Table 2-6 defines the possible combinations of the signals and the frequency associated with each
combination. The required frequency is determined by the processor, chipset, and clock
synthesizer. All agents must operate at the same frequency.
The Pentium 4 processor in the 775-land package currently operates at a 533 MHz or 800 MHz
FSB frequency (selected by a 133 MHz or 200 MHz BCLK[1:0] frequency). Individual processors
will only operate at their specified FSB frequency.
For more information about these signals, refer to Section 4.2.
Table 2-6. BSEL[2:0] Frequency Table for BCLK[1:0]
Table 2-7 specifies absolute maximum and minimum ratings. Within functional operation limits,
functionality and long-term reliability can be expected.
At conditions outside functional operation condition limits, but within absolute maximum and
minimum ratings, neither functionality nor long-term reliability can be expected. If a device is
returned to conditions within functional operation limits after having been subjected to conditions
outside these limits, but within the absolute maximum and minimum ratings, the device may be
functional, but with its lifetime degraded depending on exposure to conditions exceeding the
functional operation condition limits.
At conditions exceeding absolute maximum and minimum ratings, neither functionality nor longterm reliability can be expected. Moreover, if a device is subjected to these conditions for any
length of time then, when returned to conditions within the functional operating condition limits, it
will either not function, or its reliability will be severely degraded.
Although the processor contains protective circuitry to resist damage from static electric discharge,
precautions should always be taken to avoid high static voltages or electric fields.
Table 2-7. Processor DC Absolute Maximum Ratings
SymbolParameterMinMax UnitNotes
V
CC
V
TT
T
C
T
STORAGE
NOTES:
1.For functional operation, all processor electrical, signal quality, mechanical and thermal specifications must be satisfied.
2.Excessive overshoot or undershoot on any signal will likely result in permanent damage to the processor.
3.Storage temperature is applicable to storage conditions only. In this scenario, the processor must not receive a clock, and
no lands can be connected to a voltage bias. Storage within these limits will not affect the long-term reliability of th e device.
For functional operation, refer to the processor case temperature specifications.
4.This rating applies to the processor and does not include any tray or packaging.
Core voltage with respect to
V
SS
FSB termination voltage with
respect to V
Processor case temperatureSee Section 5See Section 5°C—
Processor storage temperature –40 +85°C
SS
–0.31.55V—
–0.31.55V—
1, 2
3, 4
2.11Processor DC Specifications
The processor DC specifications in this section are defined at the processor core silicon and
not at the package lands unless noted otherwise. See Chapter 4 for the signal definiti ons and
signal assignments. Most of the signals on the processor FSB are in the GTL+ signal group. The
DC specifications for these signals are listed in Table 2-12.
Previously, legacy signals and Test Access Port (TAP) signals to the processor used low-voltage
CMOS buffer types. However , these interfaces now follow DC specifications similar to GTL+. The
DC specifications for these signal groups are listed in Table 2-11 and Table 2-13.
Table 2-8 through Table 2-15 list the DC specifications for the Pentium 4 processor in the 775-land
package and are valid only while meeting specifications for case temperature, clock frequency, and
input voltages. Care should be taken to read all notes associated with each parameter.
MSR_PLATFORM_BRV bit 18 is a Platform Requirement Bit (PRB) that indicates that the
processor has specific platform requirements.
24Datasheet
Electrical Specifications
Table 2-8. Voltage and Current Specifications (Sheet 1 of 2)
SymbolParameterMinTypMaxUnitNotes
VID rangeVID1.200—1.425V
Processor NumberCore Frequency
for 775_VR_CONFIG_04B
V
CC
processors
V
CC
570/571
560/561
550
V
CC
550/551
540/541
530/531
520/521
570/571
560/561
I
CC
550
550/551
540/541
530/531
520/521
3.80 GHZ (PRB = 1)
3.60 GHz (PRB = 1)
3.40 GHz (PRB = 1)
for 775_VR_CONFIG_04A
V
CC
processors
3.40 GHz (PRB = 0)
3.20 GHz (PRB = 0)
3 GHz (PRB = 0)
2.80 GHz (PRB = 0)
for processor with multiple
I
CC
VID
3.80 GHZ (PRB = 1)
3.60 GHz (PRB = 1)
3.40 GHz (PRB = 1)
3.40 GHz (PRB = 0)
3.20 GHz (PRB = 0)
3 GHz (PRB = 0)
2.80 GHz (PRB = 0)
Stop-Grant
I
CC
Refer to Table 2-10 and
Figure 2-3
Refer to Table 2-9 and
Figure 2-2
119
119
——
119
V
V
A
78
78
78
78
1
2
3, 4, 5, 6
3, 4, 6, 7, 8
9
I
SGNT
I
ENHANCED_AUTO_
HALT
I
TCC
V
TT
VTT_OUT I
I
TT
CC
570/571
560/561
550
550/551
540/541
530/531
520/521
570/571
560/561
550/551
540/541
530/531
520/521
ICC TCC active——I
3.80 GHZ (PRB = 1)
3.60 GHz (PRB = 1)
3.40 GHz (PRB = 1)
3.40 GHz (PRB = 0)
3.20 GHz (PRB = 0)
3 GHz (PRB = 0)
2.80 GHz (PRB = 0)
Enhanced Auto Halt
I
CC
3.80 GHZ (PRB = 1)
3.60 GHz (PRB = 1)
3.40 GHz (PRB = 0)
3.20 GHz (PRB = 0)
3 GHz (PRB = 0)
2.80 GHz (PRB = 0)
——
——
56
56
56
40
40
40
40
37
37
31
31
40
40
A
A
CC
A
FSB termination voltage (DC+AC specifications)1.141.201.26V
DC Current that may be drawn from VTT_OUT per pin——580mA
FSB termination current——3.5A
10, 11, 15
11, 15
12
13, 14
15, 16
Datasheet25
Electrical Specifications
Table 2-8. Voltage and Current Specifications (Sheet 2 of 2)
SymbolParameterMinTypMaxUnitNotes
I
CC_VCCA
I
CC_VCCIOPLL
I
CC_GTLREF
I
CCFOR PLL LANDS
I
CCFOR I/O PLL LAND
——120mA
——100mA
ICC for GTLREF——200µA
NOTES:
1.Unless otherwise noted, all specifications in this table are based on est imate s an d si mulati ons or emp irical data. These sp ecifications will be updated with characterized data from silicon measurements at a later date.
2.Each processor is programmed with a maximum valid voltage identification value (VID), which is set at manufacturing and can not be altered.
Individual maximum VID values are calibrated during manufacturing such tha t two pro cessors at th e same freque ncy may have diffe r ent se ttings
within the VID range. Note this differs from the VID employed by the processor during a power management event (Thermal Monitor 2 or Enhanced HALT State).
3.These voltages are targets only. A variable voltage source should exist on systems in th e event that a different voltage is required. Se e Section 2.4
and Table 2-2 for more information.
4.The voltage specification requirements are measured acr oss VCC_SE NSE and VS S_S ENSE lands a t the socket wit h a 100 MHz band wid th oscilloscope, 1.5 pF maximum probe capacitance, and 1 MΩ minimum impedance. The maximum l ength of ground wire on the probe should be less
than 5 mm. Ensure external noise from the system is not coupled into the oscilloscope probe.
5.Refer to Table 2-10 and Figure 2-3 for the minimum, typical, and maximum V
jected to any Vcc and Icc combination wherein V
6.775_VR_CONFIG_04A and 775_VR_CONFIG_04B refer to voltage regulator configurations that are defined in the Voltage Regulator Down(VRD) 10.1 Design Guide For Desktop LGA775 Socket.
7.Refer to Table 2-9 and Figure 2-2 for the minimum, typical, and maximum V
to any V
8.These frequencies will operate in a system designed for 775_VR_CONFIG_04B processors. The power and I
this configuration due to the improved loadline and resultin g hi gher V
9.I
cc_max
10. The current specified is also for AutoHALT State.
11. Icc Stop-Grant and I
12. The maximum instantaneous current the processor will dra w while the thermal control circuit is active as indicated by the assertion of PROCHOT#
is the same as the maximum Icc for the processor.
13. V
14. Baseboard bandwidth is limited to 20 MHz.
15. These parameters are based on design characterization and are not tested.
16. This is maximum total current drawn from V
(through the signal line). Refer to the Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket to determine the total I
and ICC combination wherein VCC exceeds V
CC
is specified at V
CC
must be provided via a separate voltage source and not be connected t o VCC. This specification is measured at the land.
TT
.
CC_max
Enhanced Auto Halt are specified at V
exceeds V
CC
CC_max
plane by only the processor. This specification does not include the current coming from R
TT
for a given current.
cc_max
for a given current.
CC
.
CC_max
drawn by the system.
allowed for a given current. The processor should not be sub-
CC
allowed for a given current. The processor should not be subjected
CC
will be incrementally higher in
.
CC
1
15
15
15
TT
TT
26Datasheet
Electrical Specifications
Table 2-9. VCC Static and Transient Tolerance for 775_VR_CONFIG_04A Processors
1.The loadline specification includes both static and transient limits except for overshoot allowed as shown in
Section 2.12.
2.This table is intended to aid in reading discrete points on Figure 2-2.
3.The loadlines specify voltage limits at the die measured at the VCC_SENSE and VSS_SENSE lands. Voltage
regulation feedback for voltage regulator circuits must be taken from processor V
the Volt age Regulator Down (VRD) 10.1 Design Guide For Deskt op LGA775 Socket for socket loadli ne guidelines and VR implementation details.
4.Adherence to this loadline specification for the processor is required to ensure reliable processor operation.
1, 2, 3, 4
Minimum Voltage
1.80 mΩ
and VSS lands. Refer to
CC
Datasheet27
Electrical Specifications
Figure 2-2. VCC Static and Transient Tolerance for 775_VR_CONFIG_04A
Icc [A]
Vcc Maximum
VID - 0.000
VID - 0.025
VID - 0.050
VID - 0.075
VID - 0.100
Vcc [V]
VID - 0.125
VID - 0.150
VID - 0.175
VID - 0.200
0 10203040506070
Vcc Typical
Vcc Minimum
NOTES:
1. The loadline specification includes both static and transient limits except for overshoot allowed as shown in Section 2.12.
2. This loadline specification shows the deviation from the VID set point.
3. The loadlines specify voltage limits at the die measured at the VCC_SENSE and VSS_SENSE lands. Voltage regulation
feedback for voltage regulator circuits must be taken from processor V
Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket for socket loadline guidelines and VR impl ementation details.
4. Adherence to this loadline specification for the processor is required to ensure reliable processor operation.
and VSS lands. Refer to the Voltage Regulator
CC
28Datasheet
Electrical Specifications
Table 2-10. VCC Static and Transient Tolerance for 775_VR_CONFIG_04B Processors
1.The loadline specification includes both static and transient limits except for overshoot allowed as shown in
Section 2.12.
2.This table is intended to aid in reading discrete points on Figure 2-2.
3.The loadlines specify voltage limits at the die measured at the VCC_SENSE and VSS_SENSE lands. Voltage
regulation feedback for voltage regulator circuits must be taken from processor V
the Volt age Regulator Down (VRD) 10.1 Design Guide For Deskt op LGA775 Socket for socket loadli ne guidelines and VR implementation details.
4.Adherence to this loadline specification for the processor is required to ensure reliable processor operation.
1, 2, 3, 4
Minimum Voltage
1.40 mΩ
and VSS lands. Refer to
CC
Datasheet29
Electrical Specifications
Figure 2-3. VCC Static and Transient Tolerance for 775_VR_CONFIG_04B
Icc [A]
Vcc Maximum
VID - 0.000
VID - 0.019
VID - 0.038
VID - 0.057
VID - 0.076
VID - 0.095
VID - 0.114
Vcc [V]
VID - 0.133
VID - 0.152
VID - 0.171
VID - 0.190
VID - 0.209
VID - 0.228
0 102030405060708090100110120
Vcc Typical
Vcc Minimum
NOTES:
1. The loadline specification includes both static and transient limits except for overshoot allowed as shown in Section 2.12.
2. This loadline specification shows the deviation from the VID set point.
3. The loadlines specify voltage limits at the die measured at the VCC_SENSE and VSS_SENSE lands. Voltage regulation
feedback for voltage regulator circuits must be taken from processor V
Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket for socket loadline guidelines and VR impl ementation details.
4. Adherence to this loadline specification for the processor is required to ensure reliable processor operation.
and VSS lands. Refer to the Voltage Regulator
CC
30Datasheet
Table 2-11 . GTL+ Asynchronous Signal Group DC Specifications
SymbolParameterMinMaxUnit Notes
V
Input Low Voltage 0.0VTT/2 – (0.10 * VTT)V
IL
V
Input High VoltageVTT/2 + (0.10 * VTT)VTTV
IH
V
R
NOTES:
1.Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2.VIL is defined as the voltage range at a receiving agent that will be interpreted as a logical low value.
3.LINT0/INTR and LINT1/NMI use GTLREF as a reference voltage. For these two signals V
4.VIH is defined as the voltage range at a receiving agent that will be interpreted as a logical high value.
5.V
6.The V
7.All outputs are open drain.
8.The maximum output current is based on maximum current handling capability of the buffer and is not specified into the test
9.Leakage to VSS with land held at VTT.
10. Leakage to VTT with land held at 300 mV.
Output High Voltage0.90*V
OH
I
Output Low Current—
OL
I
Input Leakage CurrentN/A± 200µA
LI
I
Output Leakage CurrentN/A± 200µA
LO
Buffer On Resistance812Ω-
ON
= GTLREF – (0.10 * VTT).
V
IL
and VOH may experience excursions above VTT. However, input signal drivers must comply with the signal quality spec-
IH
ifications.
referred to in these specifications refers to instantaneous VTT.
TT
load.
TT
V
TT
Electrical Specifications
V
TT
/[(0.50*R
R
ON_MIN
) +
TT_MIN
]
= GTLREF + (0.10 * VTT) and
IH
1
2, 3
3, 4, 5, 6
5, 6, 7
V
A
8
9
10
Table 2-12. GTL+ Signal Group DC Specifications
SymbolParameterMinMaxUnitNotes
V
Input Low Voltage0.0GTLREF – (0.10 * VTT)V
IL
V
Input High VoltageGTLREF + (0.10 * VTT)VTTV
IH
V
Output High Voltage0.90*V
OH
I
Output Low CurrentN/A
OL
Input Leakage CurrentN/A± 200µA
I
LI
I
Output Leakage CurrentN/A± 200µA
LO
R
Buffer On Resistance812Ω-
ON
NOTES:
1.Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2.VIL is defined as the voltage range at a receiving agent that will be interpreted as a logical low value.
3.The V
4.VIH is defined as the voltage range at a receiving agent that will be interpreted as a logical high value.
5.Leakage to VSS with land held at VTT.
referred to in these specifications is the instantaneous VTT.
TT
1
2, 3
3, 4
3
5
-
/[(0.50*R
TT
V
R
ON_MIN
TT
TT_MIN
) +
]
TT
V
V
A-
Datasheet31
Electrical Specifications
Table 2-13. PWRGOOD and TAP Signal Group DC Specifications
SymbolParameterMinMaxUnitNotes
V
V
R
NOTES:
1.Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2.All outputs are open drain.
3.V
4.The VTT referred to in these specifications refers to instantaneous VTT.
5.The maximum output current is based on maximum current handling capabil ity of the buf fer and is not specified into the test
6.Leakage to VSS with land held at VTT.
Input Hysteresis200350mV
HYS
Input low to high
V
T+
threshold voltage
Input high to low
V
T-
threshold voltage
Output High VoltageN/AV
OH
I
Output Low Current—45mA
OL
I
Input Leakage Current—± 200µA
LI
I
Output Leakage Current—± 200µA
LO
Buffer On Resistance712Ω-
ON
represents the amount of hysteresis, nominally centered about 0.5 * VTT, for all TAP inputs.
HYS
load.
0.5 * (V
0.5 * (V
TT + VHYS_MIN)
TT – VHYS_MAX
0.5 * (V
)0.5 * (V
TT + VHYS_MAX
TT – VHYS_MIN
TT
)V
)V
V
1, 2
3
4
4
4
5
6
-
Table 2-14. VTTPWRGD DC Specifications
SymbolParameterMin TypMaxUnitNotes
V
V
IH
Input Low Voltage——0.3V
IL
Input High Voltage0.9——V
Table 2-15. BSEL [2:0] and VID[5:0] DC Specifications
SymbolParameterMaxUnitNotes
RON (BSEL) Buffer On Resistance60Ω—
(VID)Buffer On Resistance60Ω—
R
ON
I
OL
I
LO
V
TOL
Max Land Current8mA—
Output Leakage Current200µA
Voltage ToleranceVTT (max)V—
NOTES:
1.Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2.These parameters are not tested and are based on design simulations.
3.Leakage to VSS with land held at 2.5 V.
Table 2-16. BOOTSELECT DC Specifications
SymbolParameterMinTypMaxUnitNotes
V
V
NOTES:
1.These parameters are not tested and are based on design simulations.
Input Low Voltage——0.24V
IL
Input High Voltage0.96——V—
IH
1,2
3
1
32Datasheet
2.12VCC Overshoot Specification
The Pentium 4 processor in the 775-land package can tolerate short transient overshoot events
where V
This overshoot cannot exceed VID + V
voltage). The time duration of the overshoot event must not exceed T
maximum allowable time duration above VID). These specifications apply to the processor die
voltage as measured across the VCC_SENSE and VSS_SENSE lands.
exceeds the VID voltage when transitioning from a high to low current load condition.
CC
OS_MAX
(V
OS_MAX
Electrical Specifications
is the maximum allowable overshoot
OS_MAX
(T
OS_MAX
is the
Table 2-17. V
Overshoot Specifications
CC
SymbolParameterMinTypMaxUnitFigure
V
OS_MAX
T
OS_MAX
Magnitude of VCC
overshoot above VID
Time dura tion of VCC
overshoot above VID
——0.050V2-4
—— 25 µs2-4
Figure 2-4. VCC Overshoot Example Waveform
Example Overshoot Waveform
VID + 0.050
VID
Voltage (V)
V
OS
T
OS
Time
TOS: Overshoot time above VID
V
: Overshoot above VID
OS
NOTES:
1. V
is measured overshoot voltage.
OS
2. T
is measured time duration above VID.
OS
2.12.1Die Voltage Validation
Overshoot events from application testing on real processors must meet the specifications in
Table 2-17 when measured across the VCC_SENSE and VSS_SENSE lands. Overshoot events that
are < 10 ns in duration may be ignored. These measurements of processor die level overshoot
should be taken with a 100 MHz bandwidth limited oscilloscope. Refer to the Voltage Regulator Down (VRD) 10.1 Design Guide For Desktop LGA775 Socket for additional voltage regulator
validation details.
Datasheet33
Electrical Specifications
2.13GTL+ FSB Specifications
Termination resistors are not required for most GTL+ signals, as these are integrated into the
processor silicon.Valid high and low levels are determined by the input buffers which compare a
signal’s voltage with a reference voltage called GTLREF. Table 2-18 lists the GTLREF
specifications. The GTL+ reference voltage (GTLREF) should be generated on the system board
using high precision voltage divider circuits.
Table 2-18. GTL+ Bus Voltage Definitions
SymbolParameterMinTypMaxUnitsNotes
GTLREF
R
PULLUP
R
TT
COMP[1:0]COMP Resistance59.860.461Ω
NOTES:
1.Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2.The tolerances for this specification have been stated generically to enable the system designer to calculate the minimum
and maximum values across the range of V
3.GTLREF should be ge nerated from V
4.The V
5.The Intel
of 210 Ω. Contact your Intel representative for further details and documentation.
6.These pull-ups are to VTT.
7.RTT is the on-die termination resistance measured at VTT/2 of the GTL+ output driver.
8.COMP resistance must be provided on the system board with 1% resistors. COMP[1:0] resistors are to VSS.
Bus Reference
Voltage
(0.98 * 0.67) * VTT0.67 * VTT(1.02 * 0.67) * V
On die pullup for
BOOTSELECT
500—5000Ω
signal
Termination
Resistance
by a voltage divider of 1% resistors or 1% matched resistors.
referred to in these specifications is the instantaneous VTT.
TT
®
915G/915GV/915P and 910GL Express chipset platforms use a pull-up resistor of 100Ω and a pull-down resistor
TT
546066Ω
.
TT
1
2, 3, 4, 5
V
TT
6
7
8
§
34Datasheet
Package Mechanical Specifications
3Package Mechanical
Specifications
The Pentium 4 processor in the 775-land package is packaged in a Flip-Chip Land Grid Array
(FC-LGA4) package that interfaces with the motherboard via an LGA775 socket. The package
consists of a processor core mounted on a substrate land-carrier. An integrated heat spreader (IHS)
is attached to the package substrate and core and serves as the mating surface for processor
component thermal solutions, such as a heatsink. Figure 3-1 shows a sketch of the processor
package components and how they are assembled together. Refer to the LGA775 Socket Mechanical Design Guide for complete details on the LGA775 socket.
The package components shown in Figure 3-1 include the following:
• Integrated Heat Spreader (IHS)
• Thermal Interface Material (TIM)
• Processor core (die)
• Package substrate
• Capacitors
Figure 3-1. Processor Package Assembly Sketch
Core (die)
IHS
IHS
Substrate
Substrate
System Board
System Board
NOTE:
1. Socket and motherboard are included for reference and are not part of processor package.
Core (die)
3.1Package Mechanical Drawing
The package mechanical drawings are shown in Figure 3-2 and Figure 3-4. The drawings include
dimensions necessary to design a thermal solution for the processor. These dimensions include:
• Package reference with tolerances (total height, length, width, etc.)
• IHS parallelism and tilt
• Land dimensions
• Top-side and back-side component keep-out dimensions
• Reference datums
TIM
TIM
Capacitors
Capacitors
LGA775 Socket
LGA775 Socket
All drawing dimensions are in mm [in].
Note: Guidelines on potential IHS flatness variation with socket load plate actuation and installation of
the cooling solution is available in the processor Thermal/Mechanical Design Guidelines.
Datasheet35
Package Mechanical Specifications
Figure 3-2. Processor Package Drawing 1
36Datasheet
Figure 3-3. Processor Package Drawing 2
Package Mechanical Specifications
Datasheet37
Package Mechanical Specifications
Figure 3-4. Processor Package Drawing 3
38Datasheet
Package Mechanical Specifications
3.2Processor Component Keep-Out Zones
The processor may contain components on the substrate that define component keep-out zone
requirements. A thermal and mechanical solution design must not intrude into the required keepout zones. Decoupling capacitors are typically mounted to either the topside or land-side of the
package substrate. See Figure 3-2 and Figure 3-3 for keep-out zones.
The location and quantity of package capacitors may change due to manufacturing efficiencies but
will remain within the component keep-in.
3.3Package Loading Specifications
Table 3-1 provides dynamic and static load specifications for the processor package. These
mechanical maximum load limits should not be exceeded during heatsink assembly, shipping
conditions, or standard use condition. Also, any mechanical system or component testing should
not exceed the maximum limits. The processor package substrate should not be used as a
mechanical reference or load-bearing surface for thermal and mechanical solution. The minimum
.
Table 3-1. Processor Loading Specifications
loading specification must be maintained by any thermal and mechanical solutions.
ParameterMinimumMaximumNotes
Static80 N [18 lbf]311 N [70 lbf]
Dynamic—756 N [170 lbf]
NOTES:
1.These specifications apply to uniform compressive loading in a direction normal to the processor IHS.
2.This is the maximum force that can be applied by a heatsink retention clip. The cl ip must also provide the mini mum specified
load on the processor package.
3.These specifications are based on limited testing for design characterization. Loading limits are for the package only and
does not include the limits of the processor socket.
4.Dynamic loading is defined as the sum of the load on the package from a 1 lb heatsink mass accelerating through a 11 ms
trapezoidal pulse of 50 g and the maximum static load.
3.4Package Handling Guidelines
Table 3-2 includes a list of guidelines on package handling in terms of recommended maximum
loading on the processor IHS relative to a fixed substrate. These package handling loads may be
experienced during heatsink removal.
Table 3-2. Package Handling Guidelines
ParameterMaximum RecommendedNotes
Shear311 N [70 lbf]
Tensile111 N [25 lbf]
Torque3.95 N-m [35 lbf-in]
NOTES:
1.A shear load is defined as a load applied to the IHS in a direction parallel to the IHS top surface.
2.A tensile load is defined as a pulling load applied to the IHS in a direction normal to the IHS surface.
3.A torque load is defined as a twisting load applied to the IHS in an axis of rota tion normal to the IHS top surface.
4.These guidelines are based on limited testing for design characterization.
1, 2, 3
1, 3, 4
1, 4
2, 4
3, 4
Datasheet39
Package Mechanical Specifications
3.5Package Insertion Specifications
The Pentium 4 processor in the 775-land package can be inserted into and removed from a
LGA775 socket 15 times. The socket should meet the LGA775 requirements detailed in the
LGA775 Socket Mechanical Design Guide.
3.6Processor Mass Specification
The typical mass of the Pentium 4 processor in the 775-land package is 21.5 g [0.76 oz]. This mass
[weight] includes all the components that are included in the package.
3.7Processor Materials
Table 3-3 lists some of the package components and associated materials.
This chapter provides the processor land assignment and signal descriptions.
4.1Processor Land Assignments
This section contains the land listings for the Pentium 4 processor in the 775-land package. The
landout footprint is shown in Figure 4-1 and Figure 4-2. These figures represent the landout
arranged by land number and they show the physical location of each signal on the package land
array (top view). Table 4-1 is a listing of all processor lands ordered alphabetically by land (signal)
name. Table 4-2 is also a listing of all processor lands; the ordering is by land number.
Datasheet43
Land Listing and Signal Descriptions
Figure 4-1. Landout Diagram (Top View – Left Side)
AP0#U2 Common Clock Input/Output
AP1#U3 Common Clock Input/Output
BCLK0F28ClockInput
Land #Signal Buffer
Type
Direction
Table 4-1. Alphabetical Land
Assignments
Land Name
BCLK1G28ClockInput
BINIT#AD3 Common Clock Input/Output
BNR#C2 Common Clock Input/Output
BOOTSELECTY1Power/OtherInput
BPM0#AJ2 Common Clock Input/Output
BPM1#AJ1 Common Clock Input/Output
BPM2#AD2 Common Clock Input/Output
BPM3#AG2 Common Clock Input/Output
BPM4#AF2 Common Clock Input/Output
BPM5#AG3 Common Clock Input/Output
BPRI#G8 Common ClockInput
BR0#F3 Common Clock Input/Output
BSEL0G29Power/OtherOutput
BSEL1H30Power/OtherOutput
BSEL2G30Power/OtherOutput
A[35:3]# (Address) define a 2
phase 1 of the address phase, these signals transmit the address of a
transaction. In sub-phase 2, these signals transmit transaction type information.
These signals must connect the appropriate pins/lands of all agents on the
processor FSB. A[35:3]# are protected by parity signals AP[1:0]#. A[35:3]# are
source synchronous signals and are latched into the receiving buffers by
ADSTB[1:0]#.
On the active-to-inactive transition of RESET#, the processor samples a subset
of the A[35:3]# signals to determine power-on configuration. See Section 6.1 for
more details.
If A20M# (Address-20 Mask) is asserted, the processor masks physical
address bit 20 (A20#) before looking up a line in any internal cache and before
driving a read/write transaction on the bus. Asserting A20M# emulates the 8086
processor's address wrap-around at the 1-MB boundary. Assertion of A20M# is
only supported in real mode.
A20M# is an asynchronous signal. However, to ensure recognition of this signal
following an Input/Output write instruction, it must be valid along with the
TRDY# assertion of the corresponding Input/Output Write bus transaction.
ADS# (Address Strobe) is asserted to indicate the validity of the transaction
address on the A[35:3]# and REQ[4:0]# signals. All bus agents observe the
ADS# activation to begin parity checking, protocol checking, address decode,
internal snoop, or deferred reply ID match operations associated with the new
transaction.
Address strobes are used to latch A[35:3]# and REQ[4:0]# on their rising and
falling edges. Strobes are associated with signals as shown below.
ADSTB[1:0]#
AP[1:0]#
BCLK[1:0]Input
Input/
Output
Input/
Output
SignalsAssociated Strobe
REQ[4:0]#, A[16:3]# ADSTB0#
A[35:17]#ADSTB1#
AP[1:0]# (Address Parity) are driven by the request initiator along with ADS#,
A[35:3]#, and the transaction type on the REQ[4:0]#. A correct parity signal is
high if an even number of covered signals are low and low if an odd number of
covered signals are low. This allows parity to be high when all the covered
signals are high. AP[1:0]# should connect the appropriate pins/lands of all
processor FSB agents. The following table defines the coverage model of these
signals.
Request SignalsSubphase 1Subphase 2
A[35:24]#AP0#AP1#
A[23:3]#AP1#AP0#
REQ[4:0]#AP1#AP0#
The differential pair BCLK (Bus Clock) determines the FSB frequency. All
processor FSB agents must receive these signals to drive their outputs and
latch their inputs.
All external timing parameters are specified with respect to the rising edge of
BCLK0 crossing V
CROSS
.
66Datasheet
Table 4-3. Signal Description (Sheet 2 of 8)
NameTypeDescription
BINIT# (Bus Initialization) may be observed and driven by all processor FSB
agents and if used, must connect the appropriate pins/lands of all such agents.
If the BINIT# driver is enabled during power-on configuration, BINIT# is
asserted to signal any bus condition that prevents reliable future operation.
If BINIT# observation is enabled during power-on configuration, and BINIT# is
BINIT#
BNR#
BOOTSELECTInput
BPM[5:0]#
BPRI#Input
BR0#
BSEL[2:0]Output
COMP[1:0]Analog
Input/
Output
Input/
Output
Input/
Output
Input/
Output
sampled asserted, symmetric agents reset their bus LOCK# activity and bus
request arbitration state machines. The bus agents do not reset their IOQ and
transaction tracking state machines upon observation of BINIT# activation.
Once the BINIT# assertion has been observed, the bus agents will re-arbitrate
for the FSB and attempt completion of their bus queue and IOQ entries.
If BINIT# observation is disabled during power-on configuration, a central agent
may handle an assertion of BINIT# as appropriate to the error handling
architecture of the system.
BNR# (Block Next Request) is used to assert a bus stall by any bus agent
unable to accept new bus transactions. During a bus stall, the current bus
owner cannot issue any new transactions.
This input is required to determine whether the processor is installed in a
platform that supports the Pentium 4 processor in the 775-land package. The
processor will not operate if this signal is low. This input has a weak internal
pull-up to V
BPM[5:0]# (Breakpoint Monitor) are breakpoint and performance monitor
signals. They are outputs from the processor which indicate the status of
breakpoints and programmable counters used for monitoring processor
performance. BPM[5:0]# should connect the appropriate pins/lands of all
processor FSB agents.
BPM4# provides PRDY# (Probe Ready) functionality for the TAP port. PRDY#
is a processor output used by debug tools to determine processor debug
readiness.
BPM5# provides PREQ# (Probe Request) functionality for the TAP port.
PREQ# is used by debug tools to request debug operation of the processor.
These signals do not have on-die termination. Refer to Section 2.5 for
termination requirements.
BPRI# (Bus Priority Request) is used to arbitrate for ownership of the processor
FSB. It must connect the appropriate pins/lands of all processor FSB agents.
Observing BPRI# active (as asserted by the priority agent) causes all other
agents to stop issuing new requests, unless such requests are part of an
ongoing locked operation. The priority agent keeps BPRI# asserted until all of
its requests are completed, then releases the bus by de-asserting BPRI#.
BR0# drives the BREQ0# signal in the system and is used by the processor to
request the bus. During power-on configuration this signal is sampled to
determine the agent ID = 0.
This signal does not have on-die termination and must be terminated.
The BCLK[1:0] frequency select signals BSEL[2:0] are used to select the
processor input clock frequency. Table 2-6 defines the possible combinations of
the signals and the frequency associated with each combination. The required
frequency is determined by the processor, chipset and clock synthesizer. All
agents must operate at the same frequency. For more information about these
signals, including termination recommendations refer to Section 2.9.
COMP[1:0] must be terminated to V
resistors.
CC
Land Listing and Signal Descriptions
.
on the system board using precision
SS
Datasheet67
Land Listing and Signal Descriptions
Table 4-3. Signal Description (Sheet 3 of 8)
NameTypeDescription
D[63:0]# (Data) are the data signals. These signals provide a 64-bit data path
between the processor FSB agents, and must connect the appropriate pins/
lands on all such agents. The data driver asserts DRDY# to indicate a valid data
transfer.
D[63:0]# are quad-pumped signals and will, thus, be driven four times in a
common clock period. D[63:0]# are latched off the falling edge of both
DSTBP[3:0]# and DSTBN[3:0]#. Each group of 16 data signals correspond to a
pair of one DSTBP# and one DSTBN#. The following table shows the grouping
of data signals to data strobes and DBI#.
Quad-Pumped Signal Groups
D[63:0]#
DBI[3:0]#
DBR#Output
DBSY#
DEFER#Input
DP[3:0]#
Input/
Output
Input/
Output
Input/
Output
Input/
Output
Data Group
D[15:0]#00
D[31:16]#11
D[47:32]#22
D[63:48]#33
Furthermore, the DBI# signals determine the polarity of the data signals. Each
group of 16 data signals corresponds to one DBI# signal. When the DBI# signal
is active, the corresponding data group is inverted and therefore sampled active
high.
DBI[3:0]# (Data Bus Inversion) are source synchronous and indicate the
polarity of the D[63:0]# signals.The DBI[3:0]# signals are activated when the
data on the data bus is inverted. If more than half the data bits, within a 16-bit
group, would have been asserted electrically low, the bus agent may invert the
data bus signals for that particular sub-phase for that 16-bit group.
DBR# (Debug Reset) is used only in processor systems where no debug port is
implemented on the system board. DBR# is used by a debug port interposer so
that an in-target probe can drive system reset. If a debug port is implemented in
the system, DBR# is a no connect in the system. DBR# is not a processor
signal.
DBSY# (Data Bus Busy) is asserted by the agent responsible for driving data on
the processor FSB to indicate that the data bus is in use. The data bus is
released after DBSY# is de-asserted. This signal must connect the appropriate
pins/lands on all processor FSB agents.
DEFER# is asserted by an agent to indicate that a transaction cannot be
guaranteed in-order completion. Assertion of DEFER# is normally the
responsibility of the addressed memory or input/output agent. This signal must
connect the appropriate pins/lands of all processor FSB agents.
DP[3:0]# (Data parity) provide parity protection for the D[63:0]# signals. They
are driven by the agent responsible for driving D[63:0]#, and must connect the
appropriate pins/lands of all processor FSB agents.
DSTBN#/
DSTBP#
DBI#
68Datasheet
Table 4-3. Signal Description (Sheet 4 of 8)
NameTypeDescription
Land Listing and Signal Descriptions
DRDY#
DSTBN[3:0]#
DSTBP[3:0]#
FCxOtherFC signals are signals that are available for compatibility with other processors.
FERR#/PBE#Output
GTLREFInput
GTLREF_SELOutput GTLREF_SEL is used to select the appropriate chipset GTLREF voltage.
HIT#
HITM#
IERR#Output
Input/
Output
Input/
Output
Input/
Output
Input/
Output
Input/
Output
DRDY# (Data Ready) is asserted by the data driver on each data transfer,
indicating valid data on the data bus. In a multi-common clock data transfer,
DRDY# may be de-asserted to insert idle clocks. This signal must connect the
appropriate pins/lands of all processor FSB agents.
DSTBN[3:0]# are the data strobes used to latch in D[63:0]#.
FERR#/PBE# (floating point error/pending break event) is a multiplexed signal
and its meaning is qualified by STPCLK#. When STPCLK# is not asserted,
FERR#/PBE# indicates a floating-point error and will be asserted when the
processor detects an unmasked floating-point error. When STPCLK# is not
asserted, FERR#/PBE# is similar to the ERROR# signal on the Intel 387
coprocessor, and is included for compatibility with systems using MS-DOS*type floating-point error reporting. When STPCLK# is asserted, an assertion of
FERR#/PBE# indicates that the processor has a pending break event waiting
for service. The assertion of FERR#/PBE# indicates that the processor should
be returned to the Normal state. For additional information on the pending break
event functionality, including the identification of support of the feature and
enable/disable information, refer to volume 3 of the Intel Architecture Software
Developer's Manual and the Intel Processor Identification and the CPUID
Instruction application note.
GTLREF determines the signal reference level for GTL+ input signals. GTLREF
is used by the GTL+ receivers to determine if a signal is a logical 0 or logical 1.
HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction snoop operation
results. Any FSB agent may assert both HIT# and HITM# together to indicate
that it requires a snoop stall, which can be continued by reasserting HIT# and
HITM# together.
IERR# (Internal Error) is asserted by a processor as the result of an internal
error. Assertion of IERR# is usually accompanied by a SHUTDOWN transaction
on the processor FSB. This transaction may optionally be converted to an
external error signal (e.g., NMI) by system core logic. The processor will keep
IERR# asserted until the assertion of RESET#.
This signal does not have on-die termination. Refer to Section 2.5 for
termination requirements.
Datasheet69
Land Listing and Signal Descriptions
Table 4-3. Signal Description (Sheet 5 of 8)
NameTypeDescription
IGNNE# (Ignore Numeric Error) is asserted to force the processor to ignore a
numeric error and continue to execute noncontrol floating-point instructions. If
IGNNE# is de-asserted, the processor generates an exception on a noncontrol
IGNNE#Input
INIT#Input
ITP_CLK[1:0]Input
LINT[1:0]Input
LL_ID[1:0]Output
LOCK#
MCERR#
MSID[1:0]Output
Input/
Output
Input/
Output
floating-point instruction if a previous floating-point instruction caused an error.
IGNNE# has no effect when the NE bit in control register 0 (CR0) is set.
IGNNE# is an asynchronous signal. However, to ensure recognition of this
signal following an Input/Output write instruction, it must be valid along with the
TRDY# assertion of the corresponding Input/Output Write bus transaction.
INIT# (Initialization), when asserted, resets integer registers inside the
processor without affecting its internal caches or floating-point registers. The
processor then begins execution at the power-on Reset vector configured
during power-on configuration. The processor continues to handle snoop
requests during INIT# assertion. INIT# is an asynchronous signal and must
connect the appropriate pins/lands of all processor FSB agents.
If INIT# is sampled active on the active to inactive transition of RESET#, then
the processor executes its Built-in Self-Test (BIST).
ITP_CLK[1:0] are copies of BCLK that are used only in processor systems
where no debug port is implemented on the system board. ITP_CLK[1:0] are
used as BCLK[1:0] references for a debug port implemented on an interposer. If
a debug port is implemented in the system, ITP_CLK[1:0] are no connects in
the system. These are not processor signals.
LINT[1:0] (Local APIC Interrupt) must connect the appropriate pins/lands of all
APIC Bus agents. When the APIC is disabled, the LINT0 signal becomes INTR,
a maskable interrupt request signal, and LINT1 becomes NMI, a nonmaskable
interrupt. INTR and NMI are backward compatible with the signals of those
names on the Pentium processor. Both signals are asynchronous.
Both of these signals must be software configured via BIOS programming of the
APIC register space to be used either as NMI/INTR or LINT[1:0]. Because the
APIC is enabled by default after Reset, operation of these signals as LINT[1:0]
is the default configuration.
The LL_ID[1:0] signals are used to select the correct loadline slope for the
processor. LL_ID[1:0] = 00 for the Pentium 4 processor in the 775-land
package.
LOCK# indicates to the system that a transaction must occur atomically. This
signal must connect the appropriate pins/lands of all processor FSB agents. For
a locked sequence of transactions, LOCK# is asserted from the beginning of
the first transaction to the end of the last transaction.
When the priority agent asserts BPRI# to arbitrate for ownership of the
processor FSB, it will wait until it observes LOCK# de-asserted. This enables
symmetric agents to retain ownership of the processor FSB throughout the bus
locked operation and ensure the atomicity of lock.
MCERR# (Machine Check Error) is asserted to indicate an unrecoverable error
without a bus protocol violation. It may be driven by all processor FSB agents.
MCERR# assertion conditions are configurable at a system level. Assertion
options are defined by the following options:
For more details regarding machine check architecture, refer to the IA-32 Software Developer’s Manual, Volume 3: System Programming Guide.
MSID[1:0] are provided to indicate the market segment for the processor and
may be used for future processor compatibility or for keying.
• Enabled or disabled.
• Asserted, if configured, for internal errors along with IERR#.
• Asserted, if configured, by the request initiator of a bus transaction after it
observes an error.
• Asserted by any bus agent when it observes an error in a bus transaction.
70Datasheet
Table 4-3. Signal Description (Sheet 6 of 8)
NameTypeDescription
As an output, PROCHOT# (Processor Hot) will go active when the processor
temperature monitoring sensor detects that the processor has reached its
PROCHOT#
PWRGOODInput
REQ[4:0]#
RESET#Input
RS[2:0]#Input
RSP#Input
SKTOCC#Output
SMI#Input
Input/
Output
Input/
Output
maximum safe operating temperature. This indicates that the processor
Thermal Control Circuit (TCC) has been activated, if enabled. As an input,
assertion of PROCHOT# by the system will activate the TCC, if enabled. The
TCC will remain active until the system de-asserts PROCHOT#. See
Section 5.2.4 for more details.
PWRGOOD (Power Good) is a processor input. The processor requires this
signal to be a clean indication that the clocks and power supplies are stable and
within their specifications. ‘Clean’ implies that the signal will remain low
(capable of sinking leakage current), without glitches, from the time that the
power supplies are turned on until they come within specification. The signal
must then transition monotonically to a high state. PWRGOOD can be driven
inactive at any time, but clocks and power must again be stable before a
subsequent rising edge of PWRGOOD. The PWRGOOD signal must be
supplied to the processor; it is used to protect internal circuits against voltage
sequencing issues. It should be driven high throughout boundary scan
operation.
REQ[4:0]# (Request Command) must connect the appropriate pins/lands of all
processor FSB agents. They are asserted by the current bus owner to define
the currently active transaction type. These signals are source synchronous to
ADSTB0#. Refer to the AP[1:0]# signal description for a details on parity
checking of these signals.
Asserting the RESET# signal resets the processor to a known state and
invalidates its internal caches without writing back any of their contents. For a
power-on Reset, RESET# must stay active for at least one millisecond after
V
and BCLK have reached their proper specifications. On observing active
CC
RESET#, all FSB agents will de-assert their outputs within two clocks. RESET#
must not be kept asserted for more than 10 ms while PWRGOOD is asserted.
A number of bus signals are sampled at the active-to-inactive transition of
RESET# for power-on configuration. These configuration options are described
in the Section 6 .1 .
This signal does not have on-die termination and must be terminated on the
system board.
RS[2:0]# (Response Status) are driven by the response agent (the agent
responsible for completion of the current transaction), and must connect the
appropriate pins/lands of all processor FSB agents.
RSP# (Response Parity) is driven by the response agent (the agent responsible
for completion of the current transaction) during assertion of RS[2:0]#, the
signals for which RSP# provides parity protection. It must connect to the
appropriate pins/lands of all processor FSB agents.
A correct parity signal is high if an even number of covered signals are low and
low if an odd number of covered signals are low. While RS[2:0]# = 000, RSP# is
also high, since this indicates it is not being driven by any agent guaranteeing
correct parity.
SKTOCC# (Socket Occupied) will be pulled to ground by the processor. System
board designers may use this signal to determine if the processor is present.
SMI# (System Management Interrupt) is asserted asynchronously by system
logic. On accepting a System Management Interrupt, the processor saves the
current state and enter System Management Mode (SMM). An SMI
Acknowledge transaction is issued, and the processor begins program
execution from the SMM handler.
If SMI# is asserted during the de-assertion of RESET#, the processor will tristate its outputs.
Land Listing and Signal Descriptions
Datasheet71
Land Listing and Signal Descriptions
Table 4-3. Signal Description (Sheet 7 of 8)
NameTypeDescription
STPCLK# (Stop Clock), when asserted, causes the processor to enter a low
power Stop-Grant state. The processor issues a Stop-Grant Acknowledge
transaction, and stops providing internal clock signals to all processor core units
STPCLK#Input
TCKInput
TDIInput
TDOOutput
TESTHI[13:0]Input
THERMDAOtherThermal Diode Anode. See Section 5.2.7.
THERMDCOtherThermal Diode Cathode. See Section 5.2.7.
THERMTRIP#Output
TMSInput
TRDY#Input
TRST#Input
VCCInput
VCCAInputVCCA provides isolated power for the internal processor core PLLs.
VCCIOPLLInputVCCIOPLL
VCC_SENSEOutput
VCC_MB_
REGULATION
Output
except the FSB and APIC units. The processor continues to snoop bus
transactions and service interrupts while in Stop-Grant state. When STPCLK# is
de-asserted, the processor restarts its internal clock to all units and resumes
execution. The assertion of STPCLK# has no effect on the bus clock; STPCLK#
is an asynchronous input.
TCK (Test Clock) provides the clock input for the processor Test Bus (also
known as the Test Access Port).
TDI (Test Data In) transfers serial test data into the processor. TDI provides the
serial input needed for JTAG specification support.
TDO (Test Data Out) transfers serial test data out of the processor. TDO
provides the serial output needed for JTAG specification support.
TESTHI[13:0] must be connected to the processor’s appropriate power source
(refer to VTT_OUT_LEFT and VTT_OUT_RIGHT signal description) through a
resistor for proper processor operation. See Section 2.5 for more details.
In the event of a catastrophic cooling failure, the processor will automatically
shut down when the silicon has reached a temperature approximately 20 °C
above the maximum T
processor junction temperature has reached a level beyond where permanent
silicon damage may occur. Upon assertion of THERMTRIP#, the processor will
shut off its internal clocks (thus, halting program execution) in an attempt to
reduce the processor junction temperature. To protect the processor, its core
voltage (V
Driving of the THERMTRIP# signal is enabled within 10 µs of the assertion of
PWRGOOD and is disabled on de-assertion of PWRGOOD. Once activated,
THERMTRIP# remains latched until PWRGOOD is de-asserted. While the deassertion of the PWRGOOD signal will de-assert THERMTRIP#, if the
processor’s junction temperature remains at or above the trip level,
THERMTRIP# will again be asserted within 10 µs of the assertion of
PWRGOOD.
TMS (Test Mode Select) is a JTAG specification support signal used by debug
tools.
TRDY# (Target Ready) is asserted by the target to indicate that it is ready to
receive a write or implicit writeback data transfer. TRDY# must connect the
appropriate pins/lands of all FSB agents.
TRST# (Test Reset) resets the Test Access Port (TAP) logic. TRST# must be
driven low during power on Reset.
VCC are the power pins for the processor. The voltage supplied to these pins is
determined by the VID[5:0] pins.
VCC_SENSE is an isolated low impedance connection to processor core power
(V
noise.
This land is provided as a voltage regulator feedback sense point for V
connected internally in the processor package to the sense point land U27 as
described in the Voltage Regulator-Down (VRD) 10.1 Design Guide for Desktop Socket 775.
. Assertion of THERMTRIP# (Thermal Trip) indicates the
C
) must be removed following the assertion of THERMTRIP#.
CC
provides isolated power for internal processor FSB PLLs.
). It can be used to sense or measure voltage near the silicon with little
CC
CC
. It is
72Datasheet
Table 4-3. Signal Description (Sheet 8 of 8)
NameTypeDescription
VID[5:0] (Voltage ID) signals are used to support automatic selection of power
supply voltages (V
processor and must be pulled up on the motherboard. Refer to the Voltage Regulator-Down (VRD) 10.1 Design Guide for Desktop Socket 775 for more
VID[5:0]Output
VSSInput
VSSAInputVSSA is the isolated ground for internal PLLs.
VSS_SENSEOutput
VSS_MB_
REGULATION
Output
VTTMiscellaneous voltage supply.
VTT_OUT_LEFT
Output
VTT_OUT_RIGHT
information. The voltage supply for these signals must be valid before the VR
can supply V
until the voltage supply for the VID signals becomes valid. The VID signals are
needed to support the processor voltage specification variations. See Table2-2
for definitions of these signals. The VR must supply the voltage that is
requested by the signals, or disable itself.
VSS are the ground pins for the processor and should be connected to the
system ground plane.
VSS_SENSE is an isolated low impedance connection to processor core V
can be used to sense or measure ground near the silicon with little noise.
This land is provided as a voltage regulator feedback sense point for V
connected internally in the processor package to the sense point land V27 as
described in the Voltage Regulator-Down (VRD) 10.1 Design Guide for Desktop Socket 775.
The VTT_OUT_LEFT and VTT_OUT_RIGHT signals are included to provide a
voltage supply for some signals that require termination to V
motherboard.
For future processor compatibility some signals are required to be pulled up to
VTT_OUT_LEFT or VTT_OUT_RIGHT. Refer to the following table for the
signals that should be pulled up to VTT_OUT_LEFT and VTT_OUT_RIGHT.
Pull-up SignalSignals to be Pulled Up
VTT_OUT_RIGHT
VTT_OUT_LEFT
Land Listing and Signal Descriptions
). These are open drain signals that are driven by the
CC
to the processor. Conversely, the VR output must be disabled
CC
SS
on the
TT
VTT_PWRGOOD, VID[5:0], GTLREF, TMS, TDI,
TDO, BPM[5:0], other VRD components
The VTT_SEL signal is used to select the correct V
processor.
The processor requires this input to determine that the V
and within specification.
voltage level for the
TT
voltages are stable
TT
§
Datasheet73
Land Listing and Signal Descriptions
74Datasheet
Thermal Specifications and Design Considerations
5Thermal Specifications and
Design Considerations
5.1Processor Thermal Specifications
The Pentium 4 processor in the 775-land package requires a thermal solution to maintai n
temperatures within operating limits as set forth in Section 5.1.1. Any attempt to operate the
processor outside these operating limits may result in permanent damage to the processor and
potentially other components within the system. As processor technology changes, thermal
management becomes increasingly crucial when building computer systems. Maintaining th e
proper thermal environment is key to reliable, long-term system operation.
A complete thermal solution includes both component and system level thermal management
features. Component level thermal solutions can include active or passive heatsinks attached to the
processor Integrated Heat Spreader (IHS). Typical system level thermal solutions may consist of
system fans combined with ducting and venting.
For more information on designing a component level thermal solution, refer to the Intel
Pentium
Note: The boxed processor will ship with a component thermal solution. Refer to Chapter 7 for details on
the boxed processor.
®
4 Processor on 90 nm Process in the 775-Land Package Thermal Design Guidelines.
5.1.1Thermal Specifications
T o allow for the optimal operation and long-term reliability of Intel processor-based systems, the
system/processor thermal solution should be designed such that the processor remains within the
minimum and maximum case temperature (T
Thermal Design Power (TDP) value listed per frequency in Table 5-1. Thermal solutions not
designed to provide this level of thermal capability may affect the long-term reliability of the
processor and system. For more details on thermal solution design, refer to the appropriate
processor thermal design guidelines.
The Pentium 4 processor in the 775-land package introduces a new methodology for managing
processor temperatures which is intended to support acoustic noise reduction through fan speed
control. Selection of the appropriate fan speed will be based on the temperature reported by the
processor’s thermal diode. If the diode temperature is greater than or equal to T
processor case temperature must remain at or below the temperature as specified by the thermal
profile. If the diode temperature is less than T
exceed the thermal profile, but the diode temperature must remain at or below T
that implement fan speed control must be designed to take these conditions into account. Systems
that do not alter the fan speed only need to guarantee the case temperature meets the thermal profile
specifications.
®
) specifications when operating at or below the
C
, the
. Systems
CONTROL
CONTROL
then the case temperature is permitted to
CONTROL
To determine a processor's case temperature specification based on the thermal profile, it is
necessary to accurately measure processor power dissipation.
Datasheet75
Thermal Specifications and Design Considerations
The case temperature is defined at the geometric top center of the processor IHS. Analysis indicates
that real applications are unlikely to cause the processor to consume maximum power dissipation for
sustained periods of time. Intel recommends that complete thermal solution designs target the
Thermal Design Power (TDP) indicated in Table 5-1 instead of the maximum processor power
consumption. The Thermal Monitor feature is intended to help protect the processor in the unlikely
event that an application exceeds the TDP recommendation for a sustained period of time. For more
details on the usage of this feature, refer to Section 5.2. In all cases, the Thermal Monitor feature
must be enabled for the processor to remain within specification.
Table 5-1. Processor Thermal Specifications
Processor
Number
520/5212.80 (PRB = 0)845See Table 5-3 and Figure 5-2
530/5313 (PRB = 0)845See Table 5-3 and Figure 5-2
540/5413.20 (PRB = 0)845See Table 5-3 and Figure 5-2
550/5513.40 (PRB = 0)845See Table 5-3 and Figure 5-2
5503.40 (PRB = 1)1155See Table 5-2 and Figure 5-1
560/5613.60 (PRB = 1)1155See Table 5-2 and Figure 5-1
570/5713.80 (PRB = 1)1155See Table 5-2 and Figure 5-1
Core Frequency
(GHz)
Thermal Design
Power (W)
Minimum TC
(°C)
Maximum T
(°C)Notes
C
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
NOTES:
1.Thermal Design Power (TDP) should be used for processor thermal solution desi gn targets. The TDP is not the maximum power that the processor can dissipate.
2.This table shows the maximum TDP for a given frequency range. Individual pr ocessors may have a lower TDP. Therefore, the
maximum T
for the allowed combinations of power and T
will vary depending on the TDP of the individual processor. Refer to thermal profile figure and associated table
C
.
C
76Datasheet
Thermal Specifications and Design Considerations
Table 5-2. Thermal Profile for Processors with PRB = 1
Figure 5-2. Thermal Profile for Processors with PRB = 0
70.0
Power
(W)
Maximum Tc
(°C)
65.0
y = 0.28x + 44.2
60.0
55.0
Tcase (C)
50.0
45.0
40.0
0 1020304050607080
Power (W)
78Datasheet
5.1.2Thermal Metrology
The maximum and minimum case temperatures (TC) are specified in Table 5-1. These temperature
specifications are meant to help ensure proper operation of the processor. Figure 5-3 illustrates
where Intel recommends T
temperature measurement methodology, refer to the IntelProcess in the 775-Land Package Thermal Design Guidelines.
thermal measurements should be made. For detailed guidelines on
C
Thermal Specifications and Design Considerations
®
Pentium® 4 Processor on 90 nm
Figure 5-3. Case Temperature (T
37.5 mm
37.5 mm
) Measurement Location
C
37.5 mm
37.5 mm
5.2Processor Thermal Features
5.2.1Thermal Monitor
The Thermal Monitor feature helps control the processor temperature by activating the TCC when
the processor silicon reaches its maximum operating temperature. The TCC reduces processor
power consumption as needed by modulating (starting and stopping) the internal processor core
clocks. The Thermal Monitor feature must be enabled for the processor to be operating within specifications. The temperature at which Thermal Monitor activates the thermal control
circuit is not user configurable and is not software visible. Bus traffic is snooped in the normal
manner, and interrupt requests are latched (and serviced during the time that the clocks are on)
while the TCC is active.
Meas ure TCat this point
Meas ure TCat this point
(geometric center of the package)
(geometric center of the package)
When the Thermal Monitor feature is enabled, and a high temperature situation exists (i.e., TCC is
active), the clocks will be modulated by alternately turning the clocks off and on at a duty cycle
specific to the processor (typically 30–50%). Clocks often will not be off for more than
3.0 microseconds when the TCC is active. Cycle times are processor speed dependent and will
decrease as processor core frequencies increase. A small amount of hysteresis has been included to
prevent rapid active/inactive transitions of the TCC when the processor temperature is near its
maximum operating temperature. Once the temperature has dropped below the maximum
operating temperature, and the hysteresis timer has expired, the TCC goes inactive and clock
modulation ceases.
Datasheet79
Thermal Specifications and Design Considerations
With a properly designed and characterized thermal solution, it is anticipated that the TCC would
only be activated for very short periods of time when running the most power intensive
applications. The processor performance impact due to these brief periods of TCC activation is
expected to be so minor that it would be immeasurable. An under-designed thermal solution that is
not able to prevent excessive activation of the TCC in the anticipated ambient environment may
cause a noticeable performance loss, and in some cases may result in a T
specified maximum temperature and may affect the long-term reliability of the processor. In
addition, a thermal solution that is significantly under-designed may not be capable of cooling the
processor even when the TCC is active continuously. Refer to the Intel90 nm Process in the 775-Land Package Thermal Design Guidelines for information on designing
a thermal solution.
The duty cycle for the TCC, when activated by the Thermal Monitor, is factory configured and
cannot be modified. The Thermal Monitor does not require any additional hardware, software
drivers, or interrupt handling routines.
5.2.2Thermal Monitor 2
The Pentium 4 processor in the 775-land package also supports a power management capability
known as Thermal Monitor 2. This mechanism provides an efficient mechanism for limiting the
processor temperature by reducing power consumption within the processor.
that exceeds the
C
®
Pentium® 4 Processor on
When Thermal Monitor 2 is enabled, and a high temperature situation is detected, the enhanced
Thermal Control Circuit (TCC) will be activated. This enhanced TCC causes the processor to
adjust its operating frequency (bus multiplier) and input voltage (VID). This combination of
reduced frequency and VID results in a decrease in processor power consumption.
A processor enabled for Thermal Monitor 2 includes two operating points, each consisting of a
specific operating frequency and voltage. The first point represents the normal operating conditions
for the processor.
The second point consists of both a lower operating frequency and voltage. When the enhanced
TCC is activated, the processor automatically transitions to the new frequency. This transition
occurs very rapidly (on the order of 5 µs). During the frequency transition, the processor is unable
to service any bus requests, and consequently, all bus traffic is blocked. Edge-triggered interrupts
will be latched and kept pending until the processor resumes operation at the new frequency.
Once the new operating frequency is engaged, the processor will transition to the new core
operating voltage by issuing a new VID code to the voltage regulator. The voltage regulator must
support VID transitions in order to support Thermal Monitor 2. During the voltage change, it will
be necessary to transition through multiple VID codes to reach the target operating voltage. Each
step will be one VID table entry (i.e., 12.5 mV steps). The processor continues to execute
instructions during the voltage transition. Operation at this lower voltage reduces both the dynamic
and leakage power consumption of the processor, providing a reduction in power consumption at a
minimum performance impact.
Once the processor has sufficiently cooled, and a minimum activation time has expired, the
operating frequency and voltage transition back to the normal system operating point. Transition of
the VID code will occur first, to insure proper operation once the processor reaches its normal
operating frequency. Refer to Figure 5-4 for an illustration of this ordering.
80Datasheet
Thermal Specifications and Design Considerations
Figure 5-4. Thermal Monitor 2 Frequency and Voltage Orde ring
T
f
f
TM2
MAX
TM2
Temperature
Frequency
VID
VID
TM2
VID
PROCHOT#
Time
The PROCHOT# signal is asserted when a high temperature situation is detected, regardless of
whether or not Thermal Monitor or Thermal Monitor 2 is enabled.
It should be noted that the Thermal Monitor 2 TCC can not be activated via the on demand mode.
The Thermal Monitor TCC, however, can be activated through the use of the on demand mode.
5.2.3On-Demand Mode
The Pentium 4 processor in the 775-land package provides an auxiliary mechanism that allows
system software to force the processor to reduce its power consumption. This mechanism is
referred to as "On-Demand" mode and is distinct from the Thermal Monitor feature. On-Demand
mode is intended as a means to reduce system level power consumption. Systems using the
Pentium 4 processor in the 775-land package must not rely on software usage of this mechanism to
limit the processor temperature.
If bit 4 of the ACPI P_CNT Control Register (located in the processor IA32_THERM_CONTROL
MSR) is written to a '1', the processor will immediately reduce its power consumption via
modulation (starting and stopping) of the internal core clock, independent of the processor
temperature. When using On-Demand mode, the duty cycle of the clock modulation is
programmable via bits 3:1 of the same ACPI P_CNT Control Register. In On-Demand mode, the
duty cycle can be programmed from 12.5% on/ 87.5% off, to 87.5% on/12.5% off in 12.5%
increments. On-Demand mode may be used in conjunction with the Thermal Monitor. If the system
tries to enable On-Demand mode at the same time the TCC is engaged, the factory configured duty
cycle of the TCC will override the duty cycle selected by the On-Demand mode.
Datasheet81
Thermal Specifications and Design Considerations
5.2.4PROCHOT# Signal
An external signal, PROCHOT# (processor hot), is asserted when the processor die temperature
has reached its maximum operating temperature. If the Thermal Monitor is enabled (note that the
Thermal Monitor must be enabled for the processor to be operating within specification), the TCC
will be active when PROCHOT# is asserted. The processor can be configured to generate an
interrupt upon the assertion or de-assertion of PROCHOT#. Refer to the Intel Architecture Software Developer's Manuals for specific register and programming details.
The Pentium 4 processor in the 775-land package implements a bi-directional PROCHOT#
capability to allow system designs to protect various components from over-temperature situations.
The PROCHOT# signal is bi-directional in that it can either signal when the processor has reached
its maximum operating temperature or be driven from an external source to activate the TCC. The
ability to activate the TCC via PROCHOT# can provide a means for thermal protection of system
components.
One application is the thermal protection of voltage regulators (VR). System designers can create a
circuit to monitor the VR temperature and activate the TCC when the temperature limit of the VR
is reached. By asserting PROCHOT# (pulled-low) and activating the TCC, the VR can cool down
as a result of reduced processor power consumption. Bi-directional PROCHOT# can allow VR
thermal designs to target maximum s ustain ed curr ent instead of maximum current. Systems should
still provide proper cooling for the VR, and rely on bi-directional PROCHOT# only as a backup in
case of system cooling failure. The system thermal design should allow the power delivery
circuitry to operate within its temperature specification even while the processor is operating at its
Thermal Design Power. With a properly designed and characterized thermal solution, it is
anticipated that bi-directional PROCHOT# would only be asserted for very short periods of time
when running the most power intensive applications. An under-designed thermal solution that is
not able to prevent excessive assertion of PROCHOT# in the anticipated ambient environment may
cause a noticeable performance loss. Refer to the Voltage Regulator-Down (VRD) 10.1 Design Guide for Desktop Socket 775 for details on implementing the bi-directional PROCHOT# feature.
5.2.5THERMTRIP# Signal
Regardless of whether or not the Thermal Monitor feature is enabled, in the event of a catastrophic
cooling failure, the processor will automatically shut down when the silicon has reached an
elevated temperature (refer to the THERMTRIP# definition in Table 4-3). At this point, the FSB
signal THERMTRIP# will go active and stay active as described in Table 4-3. THERMTRIP#
activation is independent of processor activity and does not generate any bus cycles.
5.2.6T
82Datasheet
CONTROL
T
CONTROL
The value for T
When T
profile in Table 5-2
T
The purpose of this feature is to support acoustic optimization through fan speed control. Contact
your Intel representative for further details and documentation.
diode
CONTROL
and Fan Speed Reduction
is a temperature specification based on a temperature reading from the thermal diode.
CONTROL
is above T
(or lower) as measured by the thermal diode.
will be calibrated in manufacturing and configured for each processor.
CONTROL
and Figure 5-1; otherwise, the processor temperature can be maintained at
, then TC must be at or below T
as defined by the thermal
C-MAX
5.2.7Thermal Diode
The processor incorporates an on-die thermal diode. A thermal sensor located on the system board
may monitor the die temperature of the processor fo r th ermal management/long term die
temperature change purposes. Table 5-4 and Table 5-5 provide the diode parameter and interface
specifications. This thermal diode is separate from the Thermal Monitor’s thermal sensor and
cannot be used to predict the behavior of the Thermal Monitor.
Table 5-4. Thermal Diode Parameters
SymbolParameterMinTypMaxUnitNotes
I
Forward Bias Current11187µA
FW
nDiode Ideality Factor1.00831.0111.023
R
Series Resistance3.2423.333.594Ω
T
NOTES:
1.Intel does not support or recommend operation of the thermal diode under reverse bias.
2.Characterized at 75 °C.
3.Not 100% tested. Specified by design characterization.
4.The ideality factor, n, represents the deviation from ideal diode behavior as exemplified by the diode equation:
where I
Constant, and T = absolute temperature (Kelvin).
5.Devices found to have an ideality factor of 1.0183 to 1.023 will create a temperature error approximately 2C° higher than
6.The series resistance, RT, is provided to allow for a more accurate measurement of the thermal diode temperature. RT, as
where T
charge.
= saturation current, q = electronic charge, VD = voltage across the diode, k = Boltzmann
S
the actual temperature. To minimize any potential acoust ic impact of th is temp erat ure error , T
2 C° on these parts.
defined, includes the pins of the processor but does not include any socket resistance or board trace resistance between
the socket and the external remote diode thermal sensor. RT can be used by remote diode thermal sensors with automatic
series resistance cancellation to calibrate out this error term. Another application is that a temperature offset can be manually calculated and programmed into an offset register in the remote diode thermal sensors as exemplified by the equation:
= sensor temperature error, N = sensor current ratio, k = Boltzmann Constant, q = electronic
error
IFW = IS * (e
T
= [RT * (N-1) * I
error
Thermal Specifications and Design Considerations
1
2, 3, 4, 5
2, 3, 6
qVD/nkT
–1)
will be increased by
CONTROL
] / [nk/q * ln N]
FWmin
Table 5-5. Thermal Diode Interface
Signal NameLand NumberSignal Description
THERMDAAL1diode anode
THERMDCAK1diode cathode
§
Datasheet83
Thermal Specifications and Design Considerations
84Datasheet
6Features
6.1Power-On Configuration Options
Several configuration options can be configured by hardware. The Pentium 4 processor in the 775land package samples the hardware configuration at reset, on the active-to-inactive transition of
RESET#. For specifications on these options, refer to Table 6-1.
The sampled information configures the processor for subsequent operation. These configuration
options cannot be changed except by another reset. All resets reconfigure the processor; for reset
purposes, the processor does not distinguish between a "warm" reset and a "power-on" reset.
Frequency determination functionality will exist on engineering sample processors which means
that samples can run at varied frequencies. Production material will have the bus to core ratio
locked and can only be operated at the rated frequency.
Table 6-1. Power-On Configuration Option Signals
Configuration OptionSignal
Output tristateSMI#
Execute BISTINIT#
In Order Queue pipelining (set IOQ depth to 1)A7#
Disable MCERR# observationA9#
Disable BINIT# observationA10#
APIC Cluster ID (0-3)A[12:11]#
Disable bus parkingA15#
Disable Hyper-Threading TechnologyA31#
Symmetric agent arbitration IDBR0#
RESERVEDA[6:3]#, A8#, A[14:13]#, A[16:30]#, A[32:35]#
NOTES:
1.Asserting this signal during RESET# will select the corresponding option.
2.Address signals not identified in this table as configuration options should not be asserted during RESET#.
Features
1, 2
6.2Clock Control and Low Power States
The processor allows the use of AutoHAL T and S top-Grant states to reduce power consumption by
stopping the clock to internal sections of the processor, depending on each particular state. See
Figure 6-1 for a visual representation of the processor low power states.
The processor adds support for the Enhanced HALT powerdown state. Refer to Figure 6-1 and the
following sections.
Not all processors are capable of supporting the Enhanced HALT state. Refer to the Specification
Update to determine which processor stepping and frequencies will support the Enhanced HALT
state.
Datasheet85
Features
6.2.1Normal State
This is the normal operating state for the processor.
6.2.2HALT and Enhanced HALT Powerdown States
The Prescott processor supports the HALT or Enhanced HALT powerdown state. The Enhanced
HALT powerdown state is configured and enabled via the BIOS.
The Enhanced HALT state is a lower power state as compared to the Stop Grant State.
If Enhanced HALT is not enabled, the default powerdown state entered will be HALT. Refer to the
sections below for details about the HALT and Enhanced HALT states.
6.2.2.1HALT Powerdown State
HALT is a low power state entered when all the logical processors have executed the HALT or
MWAIT instructions. When one of the logical processors executes the HALT instruction, that
logical processor is halted, however, the other processor continues normal operation. The processor
will transition to the Normal state upon the occurrence of SMI#, BINIT#, INIT#, or LINT[1:0]
(NMI, INTR). RESET# will cause the processor to immediately initialize itself.
The return from a System Management Interrupt (SMI) handler can be to either Normal Mode or
the HALT Power Down state. See the Intel Architecture Software Devel oper's Manual, Volume III: System Programmer's Guide for more information.
The system can generate a STPCLK# while the processor is in the HALT Power Down state. When
the system deasserts the STPCLK# interrupt, the processor will return execution to the HAL T state.
While in HALT Power Down state, the processor will process bus snoops.
6.2.2.2Enhanced HALT Powerdown State
Enhanced HALT is a low power state entered when all logical processors have executed the HAL T
or MWAIT instructions and Enhanced HALT has been enabled via the BIOS. When one of the
logical processors executes the HALT instruction, that log ical processor is halted; however, the
other processor continues normal operation.
The processor will automatically transition to a lower frequency and voltage operating point before
entering the Enhanced HALT state. Note that the processor FSB frequency is not altered; only the
internal core frequency is changed. When entering the low power state, the processor will first
switch to the lower bus ratio and then transition to the lower VID.
While in Enhanced HALT state, the processor will process bus snoops.
The processor exits the Enhanced HAL T state when a break event occurs. When the processor exits
the Enhanced HALT state, it will first transition the VID to the original value and then change the
bus ratio back to the original value.
86Datasheet
Figure 6-1. Processor Low Power State Machine
HALT or MWAIT Instruction and
Normal State
Normal execution
STPCLK#
Asserted
STPCLK#
De-asserted
HALT Bus Cycle Generated
INIT#, BINIT#, INTR, NMI, SMI#,
RESET#, FSB interrupts
PCL
ST
Asserte
Features
Enhanced HALT or HALT State
BCLK running
Snoops and interrupts allowed
#
K
d
#
serted
PCLK
ST
e-as
D
Snoop
Event
Occurs
HALT Snoop State
BCLK running
Service snoops to caches
Snoop
Event
Serviced
Stop-Grant State
BCLK running
Snoops and interrupts allowed
6.2.3Stop-Grant State
When the STPCLK# signal is asserted, the Stop-Grant state of the processor is entered 20 bus
clocks after the response phase of the processor-issued Stop Grant Acknowledge special bus cycle.
Since the GTL+ signals receive power from the FSB, these signals should not be driven (allowing
the level to return to V
addition, all other input signals on the FSB should be driven to the inactive state.
BINIT# will not be serviced while the processor is in Stop-Grant state. The event will be latched
and can be serviced by software upon exit from the Stop Grant state.
RESET# will cause the processor to immediately initialize itself, but the processor will stay in
Stop-Grant state. A transition back to the Normal state will occur with the de-assertion of the
STPCLK# signal.
A transition to the HALT/Grant Snoop state will occur when the processor detects a snoop on the
FSB (see Section 6.2.3).
While in the Stop-Grant State, SMI#, INIT#, BINIT# and LINT[1:0] will be latched by the
processor, and only serviced when the processor returns to the Normal State. Only one occurrence
of each event will be recognized upon return to the Normal state.
) for minimum power drawn by the termination resistors in this state. In
TT
Snoop Event Occurs
Snoop Event Serviced
Grant Snoop State
BCLK running
Service snoops to caches
While in Stop-Grant state, the processor will process a FSB snoop.
Datasheet87
Features
6.2.4Enhanced HALT Snoop or HALT Snoop State, Grant Snoop
State
The Enhanced HALT Snoop State is used in conjunction with the new Enhanced HALT state. If
Enhanced HALT state is not enabled in the BIOS, the default Snoop State entered will be the
HALT Snoop State. Refer to the sections below for details on HALT Snoop State, Grant Snoop
State and Enhanced HALT Snoop State.
6.2.4.1HALT Snoop State, Grant Snoop State
The processor will respond to snoop transactions on the FSB while in Stop-Grant state or in HALT
Power Down state. During a snoop transaction, the processor enters the HALT:Grant Snoop state.
The processor will stay in this state until the snoop on the FSB has been serviced (whether by the
processor or another agent on the FSB). After the snoop is serviced, the processor will return to the
Stop-Grant state or HALT Power Down state, as appropriate.
6.2.4.2Enhanced HALT Snoop State
The Enhanced HALT Snoop State is the default Snoop State when the Enhanced HALT state is
enabled via the BIOS. The processor will remain in the lower bus ratio and VID operating point of
the Enhanced HALT state.
While in the Enhanced HALT Snoop State, snoops are handled the same way as in the HALT
Snoop State. After the snoop is serviced the processor will return to the Enhanced HALT Power
Down state.
§
88Datasheet
Boxed Processor Specifications
7Boxed Processor Specifications
The Pentium 4 processor on 90 nm process in the 775-land package will also be offered as a boxed
Intel processor. Boxed Intel processors are intended for system integrators who build systems from
baseboards and standard components. The boxed Pentium 4 processor in the 775-land package will
be supplied with a cooling solution. This chapter documents baseboard and system requirements
for the cooling solution that will be supplied with the boxed Pentium 4 processor in the 775-land
package. This chapter is particularly important for OEMs that manufacture baseboards for system
integrators. Unless otherwise noted, all figures in this chapter are dimensioned in millimeters and
inches [in brackets]. Figure 7-1 shows a mechanical representation of a boxed Pentium 4 processor
in the 775-land package.
Note: Drawings in this section reflect only the specifications on the boxed Intel processor product. These
dimensions should not be used as a generic keep-out zone for all cooling solutions. It is the system
designers’ responsibility to consider their proprietary cooling solution when designing to the
required keep-out zone on their system platforms and chassis. Refer to the IntelProcessor on 90 nm Process in the 775-Land Package Thermal Design Guidelines for further
Figure 7-1. Mechanical Representation of the Boxed Processor
guidance. Contact your local Intel Sales Representative for this document.
®
Pentium® 4
NOTE: The airflow of the fan heatsink is into the center and out of the sides of the fan heatsink.
Datasheet89
Boxed Processor Specifications
7.1Mechanical Specifications
7.1.1Boxed Processor Cooling Solution Dimensions
This section documents the mechanical specifications of the boxed Pentium 4 processor on 90 nm
process in the 775-land package. The boxed processor will be shipped with an unattached fan
heatsink. Figure 7-1 shows a mechanical representation of the boxed Pentium 4 processor in the
775-land package.
Clearance is required around the fan heatsink to ensure unimpeded airflow for proper cooling. The
physical space requirements and dimensions for the boxed processor with assembled fan heatsink
are shown in Figure 7-2 (side view), and Figure 7-3 (top view). The airspace requirements for the
boxed processor fan heatsink must also be incorporated into new baseboard and system designs.
Airspace requirements are shown in Figure 7-7 and Figure 7-8. Note that some figures have
centerlines shown (marked with alphabetic designations) to clarify relative dimensioning.
Figure 7-2. Space Requirements for the Boxed Processor (Side View)
3.74
[95.0]
3.2
[81.3]
0.39
[10.0]
Figure 7-3. Space Requirements for the Boxed Processor (Top View)
3.74
[95.0]
3.74
[95.0]
0.98
[25.0]
NOTES:
1. Diagram does not show the attached hardware for the clip design and is provided only as a mechanical
representation.
90Datasheet
Boxed Processor Specifications
Figure 7-4. Space Requirements for the Boxed Processor (Overall View)
7.1.2Boxed Processor Fan Heatsink Weight
The boxed processor fan heatsink will not weigh more than 450 grams. See Chapter 5 and the
®
Intel
Pentium® 4 Processor on 90 nm Process in the 775-Land Package Thermal Design
Guidelines for details on the processor weight and heatsink requirements.
7.1.3Boxed Processor Retention Mechanism and Heatsink
Attach Clip Assembly
The boxed processor thermal solution requires a heatsink attach clip assembly, to secure the
processor and fan heatsink in the bas eboard socket. The boxed processor will ship with the heatsink
attach clip assembly.
7.2Electrical Requirements
7.2.1Fan Heatsink Power Supply
The boxed processor's fan heatsink requires a +12 V power supply. A fan power cable will be
shipped with the boxed processor to draw power from a power header on the baseboard. The power
cable connector and pinout are shown in Figure 7-5. Baseboards must provide a matched power
header to support the boxed processor. Table 7-1 contains specifications for the input and output
signals at the fan heatsink connector.
Datasheet91
Boxed Processor Specifications
The fan heatsink outputs a SENSE signal that is an open-collector output that pulses at a rate of
2 pulses per fan revolution. A baseboard pull-up resistor provides V
OH
mounted fan speed monitor requirements, if applicable. Use of the SENSE signal is optional. If the
SENSE signal is not used, pin 3 of the connector should be tied to GND.
The fan heatsink receives a PWM signal from the motherboard from the 4th pin of the connector
labeled as CONTROL.
The boxed processor's fan heatsink requires a constant +12 V supplied to pin 2 and does not
support variable voltage control or 3-pin PWM control.
The power header on the baseboard must be positioned to allow the fan heatsink power cable to
reach it. The power header identification and location should be documented in the platform
documentation, or on the system board itself. Figure 7-6 shows the location of the fan power
connector relative to the processor socket. The baseboard power header should be positioned
within 110 mm [4.33 inches] from the center of the processor socket.
Figure 7-5. Boxed Processor Fan Heatsink Power Cable Connector Description
Signal
Pin
1
2
3
4
GND
+12 V
SENSE
CONTROL
Straight square pin, 4- pin terminal housing with
polarizi ng r ibs and friction locking ramp.
0.100" pitch, 0.025" square pin width.
Match with straight pin, fr iction l oc k header on
mainboard.
to match the system board-
34
12
Table 7-1. Fan Heatsink Power and Signal Spe cifications
DescriptionMinTypMaxUnitNotes
+12 V: 12 volt fan power supply10.21213.8VIC:
Peak Fan current draw
Fan start-up current draw
Fan start-up current draw maximum duration
SENSE: SENSE frequency—2—
CONTROL212528kHz
NOTES:
1.Baseboard should pull this pin up to 5V with a resistor.
2.Open drain type, pulse width modulated.
3.Fan will have pull-up resistor to 4.75 V maximum of 5.25 V.
—
1.1
—
—
1.5
2.2
1.0
Boxed_Proc_PwrCable
A
A
Second
pulses per fan
revolution
-
1
2, 3
92Datasheet
Boxed Processor Specifications
Figure 7-6. Baseboard Power Header Placement Relative to Processor Socket
R4.33
B
C
[110]
7.3Thermal Specifications
This section describes the cooling requirements of the fan heatsink solution used by the boxed
processor.
7.3.1Boxed Processor Cooling Requirements
The boxed processor may be di rectly coo led wi th a fan heatsink. However, meeting the processor's
temperature specification is also a function of the thermal design of the entire system, and
ultimately the responsibility of the system integrator. The processor temperature specification is in
Chapter 5. The boxed processor fan heatsink is able to keep the processor temperature within the
specifications (see Table 5-1) in chassis that provide good thermal management. For the boxed
processor fan heatsink to operate properly , it is critical that the airflow provided to the fan heatsink
is unimpeded. Airflow of the fan heatsink is into the center and out of the sides of the fan heatsink.
Airspace is required around the fan to ensure that the airflow through the fan heatsink is not
blocked. Blocking the airflow to the fan heatsink reduces the cooling efficiency and decreases fan
life. Figure 7-7 and Figure 7-8 illustrate an acceptable airspace clearance for the fan heatsink. The
air temperature entering the fan should be kept below 38 ºC. Again, meeting the processor's
temperature specification is the responsibility of the system integrator.
If the boxed processor fan heatsink 4-pin connector is connected to a 3-pin motherboard header it
will operate as follows:
The boxed processor fan will operate at different speeds over a short range of internal chassis
temperatures. This allows the processor fan to operate at a lower speed and noise level, while
internal chassis temperatures are low. If internal chassis temperature increases beyond a lower
set point, the fan speed will rise linearly with the internal temperature until the higher set point
is reached. At that point, the fan speed is at its maximum. As fan speed increases, so does fan
noise levels. Systems should be designed to provide adequate air around the boxed processor
fan heatsink that remains cooler then lower set point. These set points, represented in
Figure 7-9 and Table 7-2, can vary by a few degrees from fan heatsink to fan heatsink. The
internal chassis temperature should be kept below 38 ºC. Meeting the processor's temperature
specification (see Chapter 5) is the responsibility of the system integrator.
The motherboard must supply a constant +12 V to the processor's power header to ensure proper
operation of the variable speed fan for the boxed processor. Refer to Table 7-1 for the specific
requirements.
Figure 7-9. Boxed Processor Fan Heatsink Set Points
Boxed Processor Specifications
Lower Set Point
Lowest Noise Level
Increasing Fan
Speed & Noise
X
Internal Chassis Temperature (Degrees C)
YZ
Higher Set Point
Highest Noise Level
Datasheet95
Boxed Processor Specifications
Table 7-2. Fan Heatsink Power and Signal Spe cifications
Boxed Processor Fan
Heatsink Set Point (
X ≤ 30
Y = 34
Z ≥ 38
NOTES:
1.Set point variance is approximately ± 1 °C from fan heatsink to fan heatsink.
ºC)
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.
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.
When the internal chassis temperature is above or equal to this set point,
the fan operates at its highest speed.
Boxed Processor Fan SpeedNotes
1
-
-
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
). Fan RPM is modulated through the use of an ASIC located on the motherboard that
diode
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 3pin 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.
§
96Datasheet
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