Mobile Intel® Atom™ Processor N270 Single Core Datasheet May 2008 Document Number: 320032-001 INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS OTHERWISE AGREED IN WRITING BY INTEL, THE INTEL PRODUCTS ARE NOT DESIGNED NOR INTENDED FOR ANY APPLICATION IN WHICH THE FAILURE OF THE INTEL PRODUCT COULD CREATE A SITUATION WHERE PERSONAL INJURY OR DEATH MAY OCCUR. Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence or characteristics of any features or instructions marked “reserved” or “undefined.” Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. The information here is subject to change without notice. Do not finalize a design with this information. The products described in this document may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request. Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order Enhanced Intel SpeedStep® Technology for specified units of this processor available Q2/06. See the Processor Spec Finder at http://processorfinder.intel.com or contact your Intel representative for more information. Enabling Execute Disable Bit functionality requires a PC with a processor with Execute Disable Bit capability and a supporting operating system. Check with your PC manufacturer on whether your system delivers Execute Disable Bit functionality. Intel, Atom, Intel SpeedStep, and the Intel logo are trademarks of Intel Corporation in the U. S. and other countries. *Other names and brands may be claimed as the property of others. Copyright © 2008 Intel Corporation. All rights reserved. 2 Datasheet Contents 1 Introduction .....................................................................................................6 1.1 1.2 1.3 2 Low Power Features ........................................................................................10 2.1 2.2 2.3 2.4 2.5 3 4.2 4.3 Package Mechanical Specifications ..........................................................33 4.1.1 Package Mechanical Drawings ...................................................34 Processor Pin-out Assignment ................................................................34 Signal Description ................................................................................41 Thermal Specifications and Design Considerations ...............................................50 5.1 5.2 5.3 Datasheet Power and Ground Pins .........................................................................20 FSB Clock (BCLK [1:0]) and Processor Clocking ........................................20 Voltage Identification ............................................................................20 Catastrophic Thermal Protection .............................................................23 Reserved and Unused Pins .....................................................................23 FSB Frequency Select Signals (BSEL [2:0]) ..............................................23 FSB Signal Groups................................................................................24 CMOS Asynchronous Signals ..................................................................25 Maximum Ratings.................................................................................25 Processor DC Specifications ...................................................................26 Package Mechanical Specifications and Pin Information.........................................33 4.1 5 Clock Control and Low-power States .......................................................10 2.1.1 Thread Low-power State Descriptions.........................................12 2.1.2 Package Low-power State Descriptions .......................................13 Dynamic Cache Sizing...........................................................................16 Enhanced Intel SpeedStep® Technology...................................................17 Enhanced Low-Power States ..................................................................18 FSB Low Power Enhancements ...............................................................19 2.5.1 Front Side Bus ........................................................................19 Electrical Specifications....................................................................................20 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 4 Major Features.......................................................................................6 Terminology ..........................................................................................7 References ............................................................................................9 Thermal Diode .....................................................................................51 Intel® Thermal Monitor.........................................................................53 Digital Thermal Sensor..........................................................................55 5.3.1 Out of Specification Detection ...................................................56 5.3.2 PROCHOT# Signal Pin ..............................................................56 3 Figures Figure Figure Figure Figure 1. 2. 3. 4. Thread Low-power States ...................................................................11 Package Low-power States..................................................................11 Active VCC and ICC Processor Loadline .................................................28 Deeper Sleep VCC and ICC Processor Loadline .......................................29 Tables Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table 4 1. References...........................................................................................9 2. Coordination of Thread Low-power States at the Package Level ................. 12 3. Voltage Identification Definition ............................................................20 4. BSEL [2:0] Encoding for BCLK Frequency ...............................................23 5. FSB Pin Groups...................................................................................24 6. Processor Absolute Maximum Ratings ....................................................26 7. Voltage and Current Specifications for the Processors...............................27 8. FSB Differential BCLK Specifications ......................................................29 9. AGTL+ Signal Group DC Specifications ...................................................30 10. Legacy CMOS Signal Group DC Specifications ........................................31 11. Open Drain Signal Group DC Specifications ...........................................32 12. Pin-out Arranged by Signal Name ........................................................36 13. Signal Description .............................................................................41 14. Power Specifications for the Processor..................................................50 15. Thermal Diode Interface.....................................................................52 16. Thermal Diode Parameters using Transistor Model .................................52 Datasheet Revision History Document Number Revision Number 320032 001 Description Initial release. Revision Date May 2008 § Datasheet 5 Introduction 1 Introduction The Intel® Atom™ Processor N270 (code named Mobile Diamondville) is built on 45nanometer process technology — the first generation of low-power IA-32 microarchitecture specially designed for Netbook’08 Platform. In this platform, the processor supports Intel® 945GSE chipset with the I/O Controller Hub - Intel 82801GBM. Note: Throughout this document, the Intel® Atom™ Processor N270 is referred as processor. 1.1 Major Features The following list provides some of the key features on this processor: 6 • New single-core processor for mobile devices • On-die, primary 32-kB instructions cache and 24-kB write-back data cache • 533-MHz source-synchronous front side bus (FSB) • 2-Threads support • On-die 512-kB, 8-way L2 cache • Support for IA 32-bit architecture • Intel® Streaming SIMD Extensions-2 and -3 (Intel® SSE2 and Intel® SSE3) support and Supplemental Streaming SIMD Extension 3 (SSSE3) support • Micro-FCBGA8 packaging technologies • Thermal management support via Intel® Thermal Monitor 1 and Intel Thermal Monitor 2 • FSB Lane Reversal for flexible routing • Supports C0/C1(e)/C2(e)/C4(e) • L2 Dynamic Cache Sizing • Advanced power management features including Enhanced Intel SpeedStep® Technology • Execute Disable Bit support for enhanced security Datasheet Introduction 1.2 Terminology Term Datasheet Definition # 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 non-maskable 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). Front Side Bus (FSB) Refers to the interface between the processor and system core logic (also known as the GMCH chipset components). AGTL+ Advanced Gunning Transceiver Logic. Used to refer to Assisted GTL+ signaling technology on some Intel processors. CMOS Complementary metal-Oxide semiconductor. 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 landings should not be connected to any supply 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. Enhanced Intel SpeedStep® Technology Technology that provides power management capabilities to low power devices. Processor Core Processor core die with integrated L1 and L2 cache. All AC timing and signal integrity specifications are at the pads of the processor core. TDP Thermal Design Power VCC The processor core power supply VR Voltage Regulator VSS The processor ground VCCHFM VCC at Highest Frequency Mode (HFM). VCCLFM VCC at Lowest Frequency Mode (LFM). 7 Introduction Term 8 Definition VCC,BOOT Default VCC Voltage for Initial Power Up. VCCP AGTL+ Termination Voltage. VCCA PLL Supply voltage. VCCDPRSLP VCC at Deeper Sleep (C4). VCCF Fuse Power Supply. ICCDES ICC for Mobile Intel® Atom™ Processor N270 Recommended Design Target (Estimated). ICC ICC for Mobile Intel® Atom™ Processor N270 is the number that can be use as a reflection on a battery life estimates. IAH, ICC Auto-Halt ISGNT ICC Stop-Grant. IDSLP ICC Deep Sleep. dICC/dt VCC Power Supply Current Slew Rate at Processor Package Pin (Estimated). ICCA ICC for VCCA Supply. PAH Auto Halt Power. PSGNT Stop Grant Power. PDPRSLP Deeper Sleep Power. TJ Junction Temperature. Datasheet Introduction 1.3 References Material and concepts available in the following documents may be beneficial when reading this document. Table 1. References Document No./Location Document Intel® 64 and IA-32 Architectures Software Developer's Manuals • Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture http://www.intel.com/p roducts/processor/man uals/ • Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 2A: Instruction Set Reference, A-M • Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 2B: Instruction Set Reference, N-Z • Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3A: System Programming Guide • Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3B: System Programming Guide Mobile Intel® 945 Express Chipset Family Datasheet 309219 Mobile Intel® 945 Express Chipset Family Specification Update 309220 Intel® I/O Controller Hub 7 (ICH7) Family Datasheet 307013 Intel® I/O Controller Hub 7 (ICH7) Family Specification Update 307014 AP-485, Intel® Processor Identification and CPUID Instruction Application Note 241618 § Datasheet 9 Low Power Features 2 Low Power Features 2.1 Clock Control and Low-power States The processor supports low power states at the thread level and the package level. A thread may independently enter the C1/AutoHALT, C1/MWAIT, C2, C3, and C4 low power states. Package low power states include Normal, Stop Grant, Stop Grant Snoop, Sleep and Deep Sleep. When both threads are in a common low-power state the central power management logic ensures the entire processor enters the respective package low power state by initiating a P_LVLx (P_LVL2 and P_LVL3) I/O read to the chipset. The processor implements two software interfaces for requesting low power states, MWAIT instruction extensions with sub-state hints and P_LVLx reads to the ACPI P_BLK register block mapped in the processor’s I/O address space. The P_LVLx I/O reads are converted to equivalent MWAIT C-state requests inside the processor and do not directly result in I/O reads on the processor FSB. The monitor address does not need to be setup before using the P_LVLx I/O read interface. The sub-state hints used for each P_LVLx read can be configured in a software programmable MSR. If a thread encounters a chipset break event while STPCLK# is asserted, then it asserts the PBE# output signal. Assertion of PBE# when STPCLK# is asserted indicates to system logic that individual threads should return to the C0 state and the processor should return to the Normal state. Figure 1 shows the thread low-power states. Figure 2 shows the package low-power states. Table 2 provides a mapping of thread low-power states to package low power states. 10 Datasheet Low Power Features Figure 1. Thread Low-power States Figure 2. Package Low-power States Datasheet 11 Low Power Features Table 2. Coordination of Thread Low-power States at the Package Level Package State2 Thread State C0 C11 C2 C4 Normal Normal Normal Normal Normal AutoHalt AutoHalt AutoHalt C2 Normal AutoHalt Stop-Grant Stop-Grant C4 Normal AutoHalt Stop-Grant Deeper Sleep /Intel® Enhanced Deeper Sleep C0 C1 1 NOTES: 1. AutoHALT or MWAIT/C1. 2. To enter a package state, both threads must be in a common low power state. If the threads are not in a common low power state, the package state will resolve to the highest power C state. 2.1.1 Thread Low-power State Descriptions 2.1.1.1 Thread C0 State This is the normal operating state for threads in the processor. 2.1.1.2 Thread C1/AutoHALT Power-down State C1/AutoHALT is a low-power state entered when a thread executes the HALT instruction. The processor thread will transition to the C0 state upon occurrence of SMI#, INIT#, LINT [1:0] (NMI, INTR), or FSB interrupt messages. RESET# will cause the processor to immediately initialize itself. A System Management Interrupt (SMI) handler will return execution to either Normal state or the AutoHALT Power-down state. See the Intel® 64 and IA-32 Architectures Software Developer's Manuals, Volume 3A/3B: System Programmer's Guide for more information. The system can generate a STPCLK# while the processor is in the AutoHALT Powerdown state. When the system de-asserts the STPCLK# interrupt, the processor will return execution to the HALT state. While in AutoHALT Power-down state, the processor threads will process bus snoops and snoops from the other thread. The processor will enter a snoopable sub-state (not shown in Figure 1) to process the snoop and then return to the AutoHALT Power-down state. 12 Datasheet Low Power Features 2.1.1.3 Thread C1/MWAIT Power-down State C1/MWAIT is a low-power state entered when the processor thread executes the MWAIT(C1) instruction. Processor behavior in the MWAIT state is identical to the AutoHALT state except that Monitor events can cause the processor to return to the C0 state. See the Intel® 64 and IA-32 Architectures Software Developer's Manuals, Volume 2A: Instruction Set Reference, A-M and Volume 2B: Instruction Set Reference, N-Z, for more information. 2.1.1.4 Thread C2 State Individual threads of the dual-threaded processor can enter the C2 state by initiating a P_LVL2 I/O read to the P_BLK or an MWAIT(C2) instruction, but the processor will not issue a Stop-Grant Acknowledge special bus cycle unless the STPCLK# pin is also asserted. While in the C2 state, the processor will process bus snoops and snoops from the other thread. The processor thread will enter a snoopable sub-state (not shown in Figure 1) to process the snoop and then return to the C2 state. 2.1.1.5 Thread C4 State Individual threads of the processor can enter the C4 state by initiating a P_LVL4 I/O read to the P_BLK or an MWAIT(C4) instruction. If both processor threads are in C4, the central power management logic will request that the entire processor enter the Deeper Sleep package low-power state (see Section 2.1.2.6). To enable the package level Intel Enhanced Deeper Sleep state, Dynamic Cache Sizing and Intel Enhanced Deeper Sleep state fields must be configured in the software programmable MSR bit. 2.1.2 Package Low-power State Descriptions The following state descriptions assume that both threads are in a common low power state. For cases when only one thread is in a low power state (see Section 2.1.1). 2.1.2.1 Normal State This is the normal operating state for the processor. The processor remains in the Normal state when the threads are in the C0, C1/AutoHALT, or C1/MWAIT state. 2.1.2.2 Stop-Grant State When the STPCLK# pin is asserted, each thread of the processors enters the StopGrant state within 1384 bus clocks after the response phase of the processor-issued Stop-Grant Acknowledge special bus cycle. When the STPCLK# pin is de-asserted, the core returns to its previous low-power state. Since the AGTL+ signal pins receive power from the FSB, these pins should not be driven (allowing the level to return to VCCP) for minimum power drawn by the Datasheet 13 Low Power Features termination resistors in this state. In addition, all other input pins on the FSB should be driven to the inactive state. RESET# causes the processor to immediately initialize itself, but the processor will stay in Stop-Grant state. When RESET# is asserted by the system, the STPCLK#, SLP#, DPSLP#, and DPRSTP# pins must be de-asserted prior to RESET# de-assertion. When re-entering the Stop-Grant state from the Sleep state, STPCLK# should be deasserted after the de-assertion of SLP#. While in Stop-Grant state, the processor will service snoops and latch interrupts delivered on the FSB. The processor will latch SMI#, INIT# and LINT [1:0] interrupts and will service only one of each upon return to the Normal state. The PBE# signal may be driven when the processor is in Stop-Grant state. PBE# will be asserted if there is any pending interrupt or Monitor event latched within the processor. Pending interrupts that are blocked by the EFLAGS.IF bit being clear will still cause assertion of PBE#. Assertion of PBE# indicates to system logic that the entire processor should return to the Normal state. A transition to the Stop-Grant Snoop state occurs when the processor detects a snoop on the FSB (see Section 2.1.2.3). A transition to the Sleep state (see Section 2.1.2.4) occurs with the assertion of the SLP# signal. 2.1.2.3 Stop-Grant Snoop State The processor responds to snoop or interrupt transactions on the FSB while in StopGrant state by entering the Stop-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) or the interrupt has been latched. The processor returns to the Stop-Grant state once the snoop has been serviced or the interrupt has been latched. 2.1.2.4 Sleep State The Sleep state is a low-power state in which the processor maintains its context, maintains the phase-locked loop (PLL), and stops all internal clocks. The Sleep state is entered through assertion of the SLP# signal while in the Stop-Grant state. The SLP# pin should only be asserted when the processor is in the Stop-Grant state. SLP# assertion while the processor is not in the Stop-Grant state is out of specification and may result in unapproved operation. In the Sleep state, the processor is incapable of responding to snoop transactions or latching interrupt signals. No transitions or assertions of signals (with the exception of SLP#, DPSLP#, or RESET#) are allowed on the FSB while the processor is in Sleep state. Snoop events that occur while in Sleep state or during a transition into or out of Sleep state will cause unpredictable behavior. Any transition on an input signal before the processor has returned to the Stop-Grant state will result in unpredictable behavior. If RESET# is driven active while the processor is in the Sleep state, and held active as specified in the RESET# pin specification, then the processor will reset itself, ignoring the transition through Stop-Grant state. If RESET# is driven active while the processor is in the Sleep state, the SLP# and STPCLK# signals should be de-asserted immediately after RESET# is asserted to ensure the processor correctly executes the Reset sequence. 14 Datasheet Low Power Features While in the Sleep state, the processor is capable of entering an even lower power state, the Deep Sleep state, by asserting the DPSLP# pin (see Section 2.1.2.5). While the processor is in the Sleep state, the SLP# pin must be de-asserted if another asynchronous FSB event needs to occur. 2.1.2.5 Deep Sleep State The Deep Sleep state is entered through assertion of the DPSLP# pin while in the Sleep state. BCLK may be stopped during the Deep Sleep state for additional platform level power savings. BCLK stop/restart timings on appropriate chipset-based platforms with the CK505 clock chip are as follows: • Deep Sleep entry: the system clock chip may stop/tri-state BCLK within 2 BCLKs of DPSLP# assertion. It is permissible to leave BCLK running during Deep Sleep. • Deep Sleep exit: the system clock chip must start toggling BCLK within 10 BCLK periods within DPSLP# de-assertion. To re-enter the Sleep state, the DPSLP# pin must be de-asserted. BCLK can be restarted after DPSLP# de-assertion as described above. A period of 15 microseconds (to allow for PLL stabilization) must occur before the processor can be considered to be in the Sleep state. Once in the Sleep state, the SLP# pin must be de-asserted to re-enter the Stop-Grant state. While in Deep Sleep state, the processor is incapable of responding to snoop transactions or latching interrupt signals. No transitions of signals are allowed on the FSB while the processor is in Deep Sleep state. When the processor is in Deep Sleep state, it will not respond to interrupts or snoop transactions. Any transition on an input signal before the processor has returned to Stop-Grant state will result in unpredictable behavior. 2.1.2.6 Deeper Sleep State The Deeper Sleep state is similar to the Deep Sleep state but further reduces core voltage levels. One of the potential lower core voltage levels is achieved by entering the base Deeper Sleep state. The Deeper Sleep state is entered through assertion of the DPRSTP# pin while in the Deep Sleep state. The following lower core voltage level is achieved by entering the Intel Enhanced Deeper Sleep state which is a sub-state of Deeper Sleep state. Intel Enhanced Deeper Sleep state is entered through assertion of the DPRSTP# pin while in the Deep Sleep only when the L2 cache has been completely shut down. Refer to Section 2.1.2.6.1 for further details on reducing the L2 cache and entering Intel Enhanced Deeper Sleep state. In response to entering Deeper Sleep, the processor drives the VID code corresponding to the Deeper Sleep core voltage on the VID [6:0] pins. Exit from Deeper Sleep or Intel Enhanced Deeper Sleep state is initiated by DPRSTP# de-assertion when the core requests a package state other than C4 or the core requests a processor performance state other than the lowest operating point. 2.1.2.6.1 Intel Enhanced Deeper Sleep State Intel Enhanced Deeper Sleep state is a sub-state of Deeper Sleep that extends power saving capabilities by allowing the processor to further reduce core voltage once the Datasheet 15 Low Power Features L2 cache has been reduced to zero ways and completely shut down. The following events occur when the processor enters Intel Enhanced Deeper Sleep state: 2.2 • The processor issues a P_LVL4 I/O read or an MWAIT(C4) instruction and then progressively reduces the L2 cache to zero. • The processor drives the VID code corresponding to the Intel Enhanced Deeper Sleep state core voltage on the VID [6:0] pins. Dynamic Cache Sizing Dynamic Cache Sizing allows the processor to flush and disable a programmable number of L2 cache ways upon each Deeper Sleep entry under the following conditions: • The C0 timer that tracks continuous residency in the Normal package state, has not expired. This timer is cleared during the first entry into Deeper Sleep to allow consecutive Deeper Sleep entries to shrink the L2 cache as needed. • The FSB speed to processor core speed ratio is below the predefined L2 shrink threshold. If the FSB speed to processor core speed ratio is above the predefined L2 shrink threshold, then L2 cache expansion will be requested. If the ratio is zero, then the ratio will not be taken into account for Dynamic Cache Sizing decisions. Upon STPCLK# de-assertion, the core exiting Intel Enhanced Deeper Sleep state will expand the L2 cache to two ways and invalidate previously disabled cache ways. If the L2 cache reduction conditions stated above still exist when the core returns to C4 then package enters Intel Enhanced Deeper Sleep state, then the L2 will be shrunk to zero again. If the core requests a processor performance state resulting in a higher ratio than the predefined L2 shrink threshold, the C0 timer expires, then the whole L2 will be expanded upon the next interrupt event. L2 cache shrink prevention may be enabled as needed on occasion through an MWAIT(C4) sub-state field. If shrink prevention is enabled, the processor does not enter Intel Enhanced Deeper Sleep state since the L2 cache remains valid and in full size. 16 Datasheet Low Power Features 2.3 Enhanced Intel SpeedStep® Technology The processor features Enhanced Intel SpeedStep Technology. Following are the key features of Enhanced Intel SpeedStep Technology: Datasheet • Multiple voltage and frequency operating points provide optimal performance at the lowest power. • Voltage and frequency selection is software controlled by writing to processor MSRs: ⎯ If the target frequency is higher than the current frequency, VCC is ramped up in steps by placing new values on the VID pins and the PLL then locks to the new frequency. ⎯ If the target frequency is lower than the current frequency, the PLL locks to the new frequency and the VCC is changed through the VID pin mechanism. ⎯ Software transitions are accepted at any time. If a previous transition is in progress, the new transition is deferred until the previous transition completes. • The processor controls voltage ramp rates internally to ensure glitch free transitions. • Low transition latency and large number of transitions possible per second: ⎯ Processor core (including L2 cache) is unavailable for up to 10 μs during the frequency transition. — The bus protocol (BNR# mechanism) is used to block snooping. • Improved Intel® Thermal Monitor mode: ⎯ When the on-die thermal sensor indicates that the die temperature is too high, the processor can automatically perform a transition to a lower frequency and voltage specified in a software programmable MSR. ⎯ The processor waits for a fixed time period. If the die temperature is down to acceptable levels, an up transition to the previous frequency and voltage point occurs. ⎯ An interrupt is generated for the up and down Intel Thermal Monitor transitions enabling better system level thermal management. • Enhanced thermal management features: ⎯ Digital Thermal Sensor and Out of Specification detection ⎯ Intel Thermal Monitor-1 in addition to Intel Thermal Monitor-2 in case of unsuccessful Intel Thermal Monitor-2 transition. 17 Low Power Features 2.4 Enhanced Low-Power States Enhanced low-power states (C1E, C2E, C4E) optimize for power by forcibly reducing the performance state of the processor when it enters a package low-power state. Instead of directly transitioning into the package low-power state, the enhanced package low-power state first reduces the performance state of the processor by performing an Enhanced Intel SpeedStep Technology transition down to the lowest operating point. Upon receiving a break event from the package low-power state, control will be returned to software while an Enhanced Intel SpeedStep Technology transition up to the initial operating point occurs. The advantage of this feature is that it significantly reduces leakage while in the Stop-Grant and Deeper Sleep states. Note: Long-term reliability cannot be assured unless all the Enhanced Low-Power States are enabled. The processor implements two software interfaces for requesting enhanced package low-power states: MWAIT instruction extensions with sub-state hints and via BIOS by configuring a software programmable MSR bit to automatically promote package lowpower states to enhanced package low-power states. Enhanced Intel SpeedStep Technology transitions are multi-step processes that require clocked control. These transitions cannot occur when the processor is in the Sleep or Deep Sleep package low-power states since processor clocks are not active in these states. Enhanced Deeper Sleep is an exception to this rule when the Hard C4E configuration is enabled in a software programmable MSR bit. This Enhanced Deeper Sleep state configuration will lower core voltage to the Deeper Sleep level while in Deeper Sleep and, upon exit, will automatically transition to the lowest operating voltage and frequency to reduce snoop service latency. The transition to the lowest operating point or back to the original software requested point may not be instantaneous. Furthermore, upon very frequent transitions between active and idle states, the transitions may lag behind the idle state entry resulting in the processor either executing for a longer time at the lowest operating point or running idle at a high operating point. Observations and analyses show this behavior should not significantly impact total power savings or performance score while providing power benefits in most other cases. 18 Datasheet Low Power Features 2.5 FSB Low Power Enhancements The processor incorporates FSB low power enhancements: • BPRI# control for address and control input buffers • Dynamic Bus Parking • Dynamic On Die Termination disabling • Low VCCP (I/O termination voltage) The processor incorporates the DPWR# signal that controls the data bus input buffers on the processor. The DPWR# signal disables the buffers when not used and activates them only when data bus activity occurs, resulting in significant power savings with no performance impact. BPRI# control also allows the processor address and control input buffers to be turned off when the BPRI# signal is inactive. Dynamic Bus Parking allows a reciprocal power reduction in chipset address and control input buffers when the processor de-asserts its BR0# pin. The on-die termination on the processor FSB buffers is disabled when the signals are driven low, resulting in additional power savings. The low I/O termination voltage is on a dedicated voltage plane independent of the core voltage, enabling low I/O switching power at all times. 2.5.1 Front Side Bus The processor has only one signaling mode, where the data and address buses and the strobe signals are operating in GTL mode. The reason to use GTL is to improve signal integrity. § Datasheet 19 Electrical Specifications 3 Electrical Specifications 3.1 Power and Ground Pins For clean, on-chip power distribution, the processor will have a large number of VCC (power) and VSS (ground) inputs. All power pins must be connected to VCC power planes while all VSS pins must be connected to system ground planes. Use of multiple power and ground planes is recommended to reduce I*R drop. The processor VCC pins must be supplied the voltage determined by the VID (Voltage ID) pins. 3.2 FSB 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 processor core frequency is a multiple of the BCLK [1:0] frequency. The processor uses a differential clocking implementation. 3.3 Voltage Identification The processor uses seven voltage identification pins (VID [6:0]) to support automatic selection of power supply voltages. The VID pins for the processor are CMOS outputs driven by the processor VID circuitry. Table 3 specifies the voltage level corresponding to the state of VID [6:0]. A “1” in this refers to a high-voltage level and a “0” refers to low-voltage level. Table 3. Voltage Identification Definition 20 VID6 VID5 VID4 VID3 VID2 VID1 VID0 VCC (V) 0 0 1 1 0 0 0 1.2000 0 0 1 1 0 0 1 1.1875 0 0 1 1 0 1 0 1.1750 0 0 1 1 0 1 1 1.1625 0 0 1 1 1 0 0 1.1500 0 0 1 1 1 0 1 1.1375 0 0 1 1 1 1 0 1.1250 0 0 1 1 1 1 1 1.1125 0 1 0 0 0 0 0 1.1000 0 1 0 0 0 0 1 1.0875 0 1 0 0 0 1 0 1.0750 Datasheet Electrical Specifications Datasheet VID6 VID5 VID4 VID3 VID2 VID1 VID0 VCC (V) 0 1 0 0 0 1 1 1.0625 0 1 0 0 1 0 0 1.0500 0 1 0 0 1 0 1 1.0375 0 1 0 0 1 1 0 1.0250 0 1 0 0 1 1 1 1.0125 0 1 0 1 0 0 0 1.0000 0 1 0 1 0 0 1 0.9875 0 1 0 1 0 1 0 0.9750 0 1 0 1 0 1 1 0.9625 0 1 0 1 1 0 0 0.9500 0 1 0 1 1 0 1 0.9375 0 1 0 1 1 1 0 0.9250 0 1 0 1 1 1 1 0.9125 0 1 1 0 0 0 0 0.9000 0 1 1 0 0 0 1 0.8875 0 1 1 0 0 1 0 0.8750 0 1 1 0 0 1 1 0.8625 0 1 1 0 1 0 0 0.8500 0 1 1 0 1 0 1 0.8375 0 1 1 0 1 1 0 0.8250 0 1 1 0 1 1 1 0.8125 0 1 1 1 0 0 0 0.8000 0 1 1 1 0 0 1 0.7875 0 1 1 1 0 1 0 0.7750 0 1 1 1 0 1 1 0.7625 0 1 1 1 1 0 0 0.7500 0 1 1 1 1 0 1 0.7375 0 1 1 1 1 1 0 0.7250 0 1 1 1 1 1 1 0.7125 1 0 0 0 0 0 0 0.7000 1 0 0 0 0 0 1 0.6875 1 0 0 0 0 1 0 0.6750 1 0 0 0 0 1 1 0.6625 1 0 0 0 1 0 0 0.6500 1 0 0 0 1 0 1 0.6375 21 Electrical Specifications 22 VID6 VID5 VID4 VID3 VID2 VID1 VID0 VCC (V) 1 0 0 0 1 1 0 0.6250 1 0 0 0 1 1 1 0.6125 1 0 0 1 0 0 0 0.6000 1 0 0 1 0 0 1 0.5875 1 0 0 1 0 1 0 0.5750 1 0 0 1 0 1 1 0.5625 1 0 0 1 1 0 0 0.5500 1 0 0 1 1 0 1 0.5375 1 0 0 1 1 1 0 0.5250 1 0 0 1 1 1 1 0.5125 1 0 1 0 0 0 0 0.5000 1 0 1 0 0 0 1 0.4875 1 0 1 0 0 1 0 0.4750 1 0 1 0 0 1 1 0.4625 1 0 1 0 1 0 0 0.4500 1 0 1 0 1 0 1 0.4375 1 0 1 0 1 1 0 0.4250 1 0 1 0 1 1 1 0.4125 1 0 1 1 0 0 0 0.4000 1 0 1 1 0 0 1 0.3875 1 0 1 1 0 1 0 0.3750 1 0 1 1 0 1 1 0.3625 1 0 1 1 1 0 0 0.3500 1 0 1 1 1 0 1 0.3375 1 0 1 1 1 1 0 0.3250 1 0 1 1 1 1 1 0.3125 1 1 0 0 0 0 0 0.3000 Datasheet Electrical Specifications 3.4 Catastrophic Thermal Protection The processor supports the THERMTRIP# signal for catastrophic thermal protection. An external thermal sensor should also be used to protect the processor and the system against excessive temperatures. Even with the activation of THERMTRIP#, which halts all processor internal clocks and activity, leakage current can be high enough such that the processor cannot be protected in all conditions without the removal of power to the processor. If the external thermal sensor detects a catastrophic processor temperature of 125°C (maximum), or if the THERMTRIP# signal is asserted, the VCC supply to the processor must be turned off within 500 ms to prevent permanent silicon damage due to thermal runaway of the processor. THERMTRIP# functionality is not ensured if the PWRGOOD signal is not asserted. 3.5 Reserved and Unused Pins All other RSVD signals can be left as No Connect. Connection of these pins to VCC, VSS, or to any other signal (including each other) can result in component malfunction or incompatibility with future processors. See Section 4.2 for a pin listing of the processor and the location of all RSVD pins. For reliable operation, always connect unused inputs or bidirectional signals to an appropriate signal level. Unused active low AGTL+ inputs may be left as no connects if AGTL+ termination is provided on the processor silicon. Unused active high inputs should be connected through a resistor to ground (VSS). Unused outputs can be left unconnected. 3.6 FSB 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]). These signals should be connected to the clock chip and the appropriate chipset on the platform. The BSEL encoding for BCLK [1:0] is shown in Table 4. Table 4. BSEL [2:0] Encoding for BCLK Frequency Datasheet BSEL [2] BSEL [1] BSEL [0] BCLK Frequency L L H 133 MHz 23 Electrical Specifications 3.7 FSB Signal Groups To simplify the following discussion, the FSB signals have been combined into groups by buffer type. AGTL+ input signals have differential input buffers, which use GTLREF as a reference level. In this document, the term “AGTL+ Input” refers to the AGTL+ input group as well as the AGTL+ I/O group when receiving. Similarly, “AGTL+ Output” refers to the AGTL+ output group as well as the AGTL+ 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. Asynchronous signals are still present (A20M#, IGNNE#, etc.) and can become active at any time during the clock cycle. Table 5 identifies which signals are common clock, source synchronous, and asynchronous. Table 5. FSB Pin Groups Signal Group Signals1 AGTL+ Common Clock Input Synchronous to BCLK [1:0] BPRI#, DEFER#, PREQ#4, RESET#, RS [2:0]#, TRDY#, DPWR# AGTL+ Common Clock I/O Synchronous to BCLK [1:0] ADS#, BNR#, BPM [3:0]#, BR0#, DBSY#, DRDY#, HIT#, HITM#, LOCK#, PRDY# AGTL+ Source Synchronous I/O 24 Type Synchronous to assoc. strobe Signals Associated Strobe REQ [4:0]#, A [16:3]# ADSTB0# A [31:17]# ADSTB1# D [15:0]# DSTBP0#, DSTBN0# D [31:16]# DSTBP1#, DSTBN1# D [47:32]# DSTBP2#, DSTBN2# D [63:48]# DSTBP3#, DSTBN3# AGTL+ Strobes Synchronous to BCLK [1:0] ADSTB [1:0]#, DSTBP [3:0]#, DSTBN [3:0]# CMOS Input Asynchronous DPRSTP#, DPSLP#, IGNNE#, INIT#, LINT0/INTR, LINT1/ NMI, PWRGOOD, SMI#, SLP#, STPCLK# Open Drain Output Asynchronous FERR#, THERMTRIP#, IERR# Open Drain I/O Asynchronous PROCHOT#3 CMOS Output Asynchronous VID [6:0], BSEL [2:0] CMOS Input Synchronous to TCK TCK, TDI, TMS, TRST# Datasheet Electrical Specifications Signal Group Open Drain Output Type Synchronous Signals1 TDO to TCK FSB Clock Clock Power/Other BCLK [1:0] COMP [3:0], HFPLL (old name is DBR#2), CMREF, GTLREF, TEST2/Dclk, TEST1/Aclk, THERMDA, THERMDC, VCC, VCCA, VCCP, VCC_SENSE, VSS, VSS_SENSE, VCCQ [1:0], VCCPC6 NOTES: 1. Refer to Chapter 4 for signal descriptions and termination requirements. 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. PROCHOT# signal type is open drain output and CMOS input. 3.8 CMOS Asynchronous Signals CMOS input signals are shown in Table 5. Legacy output FERR#, IERR# and other non- AGTL+ signals (THERMTRIP# and PROCHOT#) use Open Drain output buffers. These signals do not have setup or hold time specifications in relation to BCLK [1:0]. However, all of the CMOS signals are required to be asserted for more than 5 BCLKs for the processor to recognize them. See Section 3.10 for the DC specifications for the CMOS signal groups. 3.9 Maximum Ratings Table 6 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 long term 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. Datasheet 25 Electrical Specifications Table 6. Processor Absolute Maximum Ratings Symbol Parameter Min Max Unit Notes1,5 -40 85 °C 2 TSTORAGE Processor Storage Temperature VCC, VCCP Any Processor Supply Voltage with Respect to VSS -0.3 1.10 V 1 VinAGTL+ AGTL+ Buffer DC Input Voltage with Respect to VSS -0.1 1.10 V 1, 2 VinAsynch_CMOS CMOS Buffer DC Input Voltage with Respect to VSS -0.1 1.10 V 1, 2 NOTES: 1. This rating applies to the processor and does not include any tray or packaging. 2. Contact Intel for storage requirements in excess of one year. 3.10 Processor DC Specifications The processor DC specifications in this section are defined at the processor core (pads) unless noted otherwise. See Chapter 4 for the pin signal definitions and signal pin assignments. Most of the signals on the FSB are in the AGTL+ signal group. The DC specifications for these signals are listed in Table 9. DC specifications for the CMOS group are listed in Table 10. Table 9 through Table 11 list the DC specifications for the processor and are valid only while meeting specifications for junction temperature, clock frequency, and input voltages. The Highest Frequency Mode (HFM) and Lowest Frequency Mode (LFM) refer to the highest and lowest core operating frequencies supported on the processor. Active mode load line specifications apply in all states except in the Deep Sleep and Deeper Sleep states. VCC,BOOT is the default voltage driven by the voltage regulator at power up in order to set the VID values. Unless specified otherwise, all specifications for the processor are at TJ = 90°C. Note: Care should be taken to read all notes associated with each parameter. 26 Datasheet Electrical Specifications Table 7. Voltage and Current Specifications for the Processors Symbol Parameter Min Typ Max Unit 132.63 133.33 133.37 MHz Notes13 FSB Frequency BCLK Frequency VCCHFM VCC at Highest Frequency Mode (HFM) AVID - 1.10 V 1, 2, 11 VCCLFM VCC at Lowest Frequency Mode (LFM) 0.75 — AVID V 1, 2 VCC,BOOT Default VCC Voltage for Initial Power Up — 1.20 — V 2, 6 VCCP AGTL+ Termination Voltage 1.00 1.05 1.10 V VCCA PLL Supply voltage 1.425 1.5 1.575 V VCCDPRSLP VCC at Deeper Sleep (C4) 0.75 — 1.0 V VCCF Fuse Power Supply 1.00 1.05 1.10 V ICCDES ICC for Processors Recommended Design Target (Estimated) — — 4.0 A ICC for Processors — — — — — Processor Number Core Frequency/Voltage — — — — — N270 1.6GHz / 1.10V — — 3 A 3, 4 A 3, 4 A At 50°C 3, 4 ICC 1, 2 ICC Auto-Halt & Stop-Grant IAH, HFM: 1.6 GHz @ 1.10 Volts ISGNT — — 2.2 LFM: 0.8 – 1.2 GHz @ 0.75 – 1.00 Volts — — 1.5 — — 1.4 — — 0.6 ICC Deep Sleep IDSLP HFM: 1.6 GHz @ 1.10 Volts LFM: 0.8 GHz @ 0.75 – 1.00 Volts IDPRSLP ICC Deeper Sleep (C4) — — 0.2 A At 50°C 3, 4 dICC/dt VCC Power Supply Current Slew Rate at Processor Package Pin (Estimated) — — 2.5 A/µs 5, 7 ICCA ICC for VCCA Supply — — 130 mA ICCP ICCP before VCC Stable — — 2.5 A 8 ICCP ICCP after VCC Stable — — 1.5 A 9 NOTES: 1. 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 that two processors at the same frequency may have different settings within the VID range. Note that this differs from the VID employed by the processor during a power management event (Thermal Monitor 2, Enhanced Intel SpeedStep technology, or Enhanced Halt State). Typical AVID range is 0.8 V to 0.85 V. 2. The voltage specifications are assumed to be measured across VCC_SENSE and VSS_SENSE pins at socket with a 100-MHz bandwidth oscilloscope, 1.5-pF maximum probe capacitance, and 1-MΩ minimum Datasheet 27 Electrical Specifications 3. 4. 5. 6. 7. 8. 9. 10. 11. impedance. The maximum length of ground wire on the probe should be less than 5 mm. Ensure external noise from the system is not coupled in the scope probe. Specified at 90°C TJ. Specified at the nominal VCC. Measured at the bulk capacitors on the motherboard. VCC,BOOT tolerance is shown in Figure 3 and Figure 4. Based on simulations and averaged over the duration of any change in current. Specified by design/characterization at nominal VCC. Not 100% tested. This is a power-up peak current specification, which is applicable when VCCP is high and VCC_CORE is low. This is a steady-state ICC current specification, which is applicable when both VCCP and VCC_CORE are high. The VCC max supported by the process is 1.1 V but the parameter can change (burnin voltage is higher). Unless otherwise noted, all specifications in this table are based on estimates and simulations or empirical data. These specifications will be updated with characterized data from silicon measurements at a later date. Figure 3. Active VCC and ICC Processor Loadline VCC (V) Slope = -5.9 mV/A at package VCC_SENSE, VSS_SENSE pins. Differential Remote Sense required. 13 mV = Ripple VCC Max[HFM][LFM] VCC, DC Max[HFM][LFM] VCC Nom[HFM][LFM] VCC, DC Min[HFM][LFM] VCC Min[HFM][LFM] ±VCC nom*1.5 % = VR ST Pt Error 1/ ICC (A) 0 ICC max[HFM][LFM] Note 1/ VCC Set Point Error Tolerance is per below: Tolerance -------------------------------±1.5% ±11.5 mV 28 VCC Active Mode VID Code Range ---------------------------------------VCC > 0.7500 V (VID 0111100) VCC 0.7500 V (VID 0111100) Datasheet Electrical Specifications Figure 4. Deeper Sleep VCC and ICC Processor Loadline Table 8. FSB Differential BCLK Specifications Symbol Parameter Min Typ Max Unit Figure Notes1 VIH Input High Voltage — — 1.15 V 7, 8 VOH Input Low Voltage — — -0.3 V 7, 8 0.3 — 0.55 V 2, 7, 9 VCROSS Crossing Voltage ΔVCROSS Range of Crossing Points — — 140 mV 2, 7, 5 VSWING Differential Output Swing 300 — — mV 6 Input Leakage Current -5 — +5 µA 3 Pad Capacitance 1.2 1.45 2.0 pF 4 ILI Cpad NOTES: 1. Unless otherwise noted, all specifications in this table apply to all processor frequencies. 2. Crossing Voltage is defined as absolute voltage where rising edge of BCLK0 is equal to the falling edge of BCLK1. 3. For Vin between 0 V and VIH. 4. Cpad includes die capacitance only. No package parasitics are included. 5. ΔVCROSS is defined as the total variation of all crossing voltages as defined in note 2. 6. Measurement taken from differential waveform. 7. Measurement taken from single-ended waveform. 8. “Steady state” voltage, not including Overshoots or Undershoots. 9. Only applies to the differential rising edge (BCLK0 rising and BCLK1 falling). Datasheet 29 Electrical Specifications Table 9. AGTL+ Signal Group DC Specifications Symbol VCCP Parameter I/O Voltage Min Typ Max Unit 1.00 1.05 1.10 V Notes1 GTLREF GTL Reference Voltage — 2/3 VCCP — V 6 RCOMP Compensation Resistor 27.23 27.5 27.78 Ω 10 RODT Termination Resistor — 55 — Ω 11 VIH Input High Voltage GTLREF+0.10 VCCP VCCP+0.10 V 3,6 VIL Input Low Voltage -0.10 0 GTLREF–0.10 V 2,4 VOH Output High Voltage VCCP–0.10 VCCP VCCP V 6 RTT Termination Resistance Ω 7, 12 RON (GTL mode) ILI Cpad 46 [SS] 46 [CC] 55 61 [SS] 64 [CC] GTL Buffer on Resistance 21 25 29 Ω 5 Input Leakage Current — — ±100 µA 8 1.8 2.1 2.75 pF 9 Pad Capacitance NOTES: 1. Unless otherwise noted, all specifications in this table apply to all processor frequencies. 2. VIL is defined as the maximum voltage level at a receiving agent that will be interpreted as a logical low value. 3. VIH is defined as the minimum voltage level at a receiving agent that will be interpreted as a logical high value. 4. VIH and VOH may experience excursions above VCCP. However, input signal drivers must comply with the signal quality specifications. 5. This is the pull-down driver resistance. 6. GTLREF should be generated from VCCP with a 1% tolerance resistor divider. 7. RTT is the on-die termination resistance measured at VOL of the AGTL+ output driver. 8. Specified with on-die RTT and RON are turned off. 9. Cpad includes die capacitance only. No package parasitics are included. 10. There are external resistor on the comp0 and comp2 pins. 11. On-die termination resistance, measured at 0.33*VCCP. 12. SS: source synchronous pins such as quad-pumped data bus and double-pumped address bus which require a clock strobe. CC: Common clock pins. 30 Datasheet Electrical Specifications Table 10. Legacy CMOS Signal Group DC Specifications Symbol Min Typ Max Unit 1.00 1.05 1.10 V Notes1 VCCP I/O Voltage VIH Input High Voltage 0.7*VCCP VCCP VCCP+0.1 V 2 VIL Input Low Voltage CMOS -0.10 0.00 0.3*VCCP V 2, 3 VOH Output High Voltage 0.9*VCCP VCCP VCCP+0.1 V 2 VOL Output Low Voltage -0.10 0 0.1*VCCP V 2 IOH Output High Current 1.5 — 4.1 mA 5 IOL Output Low Current 1.5 — 4.1 mA 4 ILI Input Leakage Current — — ± 100 µA 6 1.6 2.1 2.55 pF 7 0.95 1.2 1.45 Cpad1 Pad Capacitance Cpad2 Pad Capacitance for CMOS Input NOTES: 1. 2. 3. 4. 5. 6. 7. 8. Datasheet Parameter 8 Unless otherwise noted, all specifications in this table apply to all processor frequencies. The VCCP referred to in these specifications refers to instantaneous VCCP. Reserved. Measured at 0.1*VCCP. Measured at 0.9*VCCP. For Vin between 0V and VCCP. Measured when the driver is tri-stated. Cpad1 includes die capacitance only for DPRSTP#, DPSLP#, PWRGOOD. No package parasitics are included. Cpad2 includes die capacitance for all other CMOS input signals. No package parasitics are included. 31 Electrical Specifications Table 11. Open Drain Signal Group DC Specifications Symbol Parameter Min Typ Max Unit Notes1 3 VOH Output High Voltage VCCP-–5% VCCP VCCP+5% V VOL Output Low Voltage 0 — 0.20 V IOL Output Low Current 16 — 50 mA 2 ILO Output Leakage Current — — ±200 µA 4 Cpad Pad Capacitance 1.9 2.2 2.45 pF 5 NOTES: 1. 2. 3. 4. 5. Unless otherwise noted, all specifications in this table apply to all processor frequencies. Measured at 0.2 VCCP. VOH is determined by value of the external pull-up resistor to VCCP. For Vin between 0 V and VOH. Cpad includes die capacitance only. No package parasitics are included. § 32 Datasheet Package Mechanical Specifications and Pin Information 4 Package Mechanical Specifications and Pin Information This chapter provides the package specifications, pin-out assignments, and signal description. 4.1 Package Mechanical Specifications The processor is available in 512 KB, 437 pins in FCBGA8 package. The package dimensions are shown in Figure . Datasheet 33 Package Mechanical Specifications and Pin Information 4.1.1 Package Mechanical Drawings Figure 5. Package Mechanical Drawing 4.2 Processor Pin-out Assignment Figure are graphic representations of the processor pin-out assignments. Table 12 lists the pin-out by signal name. 34 Datasheet Package Mechanical Specifications and Pin Information Figure 6. Pin-out Diagram (Top View, Left Side) 1 A B VSS 2 3 4 5 6 7 E F VSS 11 12 D_B54 D_B56 GTLREF VSS VCCQ0 VCCP VCCP VCCP VSS D_B60 D_B52 VSS D_B59 CMREF VSS VCCQ0 VCCP VCCP VCCP D_B63 D_B51 VSS DP_B3 VSS THRMDA THRMDC DSTBP_B VSS D_B57 3 VSS VSS VTT VCCP VCCP 13 14 CORE_D A_B35 ET VSS A_B33 15 16 17 18 19 21 A_B20 A_B32 VSS A_B34 A_B29 A_B30 A_B27 VSS A_B23 A_B17 A_B24 RSVD_3 AP_B0 VSS A_B21 A_B26 VSS A_B25 A_B19 VCC_SE VCCP A_B22 A_B28 A_B31 NSE VSS_SE VCCP VSS RESET_B VID1 NSE VSS 20 VSS VSS ADSTB_B VSS 1 VSS NC_1 VCCA VSS VTT VCCP VCCP VSS VSS VSS VTT VCCP VCCP VCCP VCCPC6 VCCPC6 VSS VSS VID5 VID2 VSS VSS VSS VTT VTT VCCP VCCP VCCP VCCPC6 VCCPC6 VID0 IERR_B VSS VSS A_B18 COMP2 COMP3 PROCHO VID4 VID6 T_B THERMT VSS VSS RIP_B G VSS D_B49 D_B40 VSS BSEL2 NC_2 VSS VTT VSS VCCP VCCP VCCP VSS VTT VID3 H D_B46 D_B41 VSS VSS BSEL1 NC_3 VSS VTT VSS VCCP VCCP VCCP VSS VTT BPM_B2 J D_B47 D_B45 D_B38 IGNNE_B VSS BSEL0 VSS VTT VSS VCCP VCCP VCCP VSS VTT BPM_B3 PREQ_B K VSS VSS VSS VTT VSS VCCP VCCP VCCP VSS VTT VSS VSS VSS VSS VTT VSS VCCP VCCP VCCP VSS VTT VSS NC_7 TMS VSS VSS A_B12 A_B16 VSS EXTBGR EF VSS VTT VSS VCCP VCCP VCCP VSS VTT NC_6 TDO TCK AP_B1 A_B10 A_B13 VSS VTT FORCEP R_B TDI VSS SLP_B A_B8 A_B5 REQ_B0 VSS MCERR_ B VSS VSS DSTBN_ DSTBP_B NC_4 B2 2 L DINV_B2 D_B43 M N P R VSS D_B35 D_B34 VSS D_B36 D_B42 D_B37 D_B33 VSS D_B44 D_B39 VSS D_B32 T COMP0 COMP1 D_B28 U D_B19 D_B27 VSS VSS DP_B2 VSS VSS NC_5 VSS VSS HFPLL VSS VSS VSS VTT VTT VSS VSS VCCP VCCP VCCP VSS VSS VTT VSS BPM_B1 A_B7 TRST_B BPM_B0 PRDY_B A_B14 A_B4 REQ_B3 A_B3 VSS VTT VSS VCCP VCCP VCCP VSS VTT VSS VSS RSP_B VSS VTT VSS VSS VSS VSS VSS VTT LINT0 FERR_B BINIT_B VSS VSS VTT VTT VTT VTT VTT VTT VTT VSS DPWR_B ACLKPH D_B26 VSS DCLKPH VSS VSS VSS DP_B0 VCCF W VSS D_B25 D_B18 D_B31 VSS D_B21 D_B20 VSS D_B15 D_B1 D_B5 D_B13 VSS D_B10 DINV_B0 RS_B1 DBSY_B BNR_B VSS HIT_B VSS VSS D_B17 D_B8 D_B7 D_B0 D_B2 VSS VSS D_B29 D_B14 VSS D_B4 VSS D_B11 D_B16 D_B23 VSS D_B3 VSS D_B6 VSS VSS DEFER_ B RS_B2 BPRI_B BR1_B DSTBN_ DSTBP_B D_B12 D_B9 B0 0 VSS VSS VSS DSTBN_ DSTBP_B DINV_B1 D_B22 D_B24 B1 1 VSS SMI_B A20M_B PWRGO INIT_B OD DRDY_B BR0_B VSS BCLK0 BCLK1 VSS VSS A_B11 ADSTB_B VSS 0 EDM VSS VSS A_B15 REQ_B1 VSS D_B30 AA VCCP VCCP VSS DP_B1 VSS VSS VCCP VSS REQ_B2 A_B9 STPCLK_ DPRSTP LINT1 DPSLP_B REQ_B4 A_B6 B _B V Y Datasheet 10 VSS DSTBN_ D_B53 B3 D_B50 9 RSVD_1 C RSVD_2 D_B48 D_B55 D_B61 DINV_B3 D_B58 D_B62 D 8 VSS ADS_B HITM_B VSS RS_B0 TRDY_B LOCK_B VSS VSS VSS VSS 35 Package Mechanical Specifications and Pin Information Table 12. Pin-out Arranged by Signal Name 36 Signal Name Ball # Signal Name Ball # Signal Name Ball # A [10]# M19 A [7]# J19 D [13]# W13 A [11]# H21 A [8]# N19 D [14]# AA9 A [12]# L20 A [9]# G20 D [15]# W9 A [13]# M20 A20M# U18 D [16]# AA5 A [14]# K19 ACLKPH U5 D [17]# Y8 A [15]# J20 ADS# V19 D [18]# W3 A [16]# L21 ADSTB [0]# K20 D [19]# U1 A [17]# C19 ADSTB [1]# B19 D [2]# Y12 A [18]# F19 BCLK [0] V11 D [20]# W7 A [19]# E21 BCLK [1] V12 D [21]# W6 A [20]# A16 BNR# Y19 D [22]# Y7 A [21]# D19 BPM [0]# K17 D [23]# AA6 A [22]# C14 BPM [1]# J18 D [24]# Y3 A [23]# C18 BPM [2]# H15 D [25]# W2 A [24]# C20 BPM [3]# J15 D [26]# V3 A [25]# E20 BPRI# U21 D [27]# U2 A [26]# D20 BR0# T20 D [28]# T3 A [27]# B18 BR1# V15 D [29]# AA8 A [28]# C15 BSEL [0] J6 D [3]# AA14 A [29]# B16 BSEL [1] H5 D [30]# V2 A [3]# P21 BSEL [2] G5 D [31]# W4 A [30]# B17 COMP [0] T1 D [32]# R3 A [31]# C16 COMP [1] T2 D [33]# R2 A [32]# A17 COMP [2] F20 D [34]# P1 A [33]# B14 COMP [3] F21 D [35]# N1 A [34]# B15 D [0]# Y11 D [36]# M2 A [35]# A14 D [1]# W10 D [37]# P2 A [4]# H20 D [10]# W15 D [38]# J3 A [5]# N20 D [11]# AA13 D [39]# N3 A [6]# R20 D [12]# Y16 D [4]# AA11 Datasheet Package Mechanical Specifications and Pin Information Datasheet Signal Name Ball # Signal Name Ball # Signal Name Ball # D [40]# G3 DEFER# T21 NC K4 D [41]# H2 DINV [0]# W16 NC K5 D [42]# N2 DINV [1]# Y6 NC M15 D [43]# L2 DINV [2]# L1 NC L16 D [44]# M3 DINV [3]# C5 PRDY# K18 D [45]# J2 DPRSTP# R18 PREQ# J16 D [46]# H1 DPWR# U4 PROCHOT# G17 D [47]# J1 DRDY# T19 PWRGOOD V17 D [48]# C2 DSTBN [0]# Y14 REQ [0]# N21 D [49]# G2 DSTBN [1]# Y4 REQ [1]# J21 D [5]# W12 DSTBN [2]# K2 REQ [2]# G19 D [50]# F1 DSTBN [3]# E2 REQ [3]# P20 D [51]# D3 DSTBP [0]# Y15 REQ [4]# R19 D [52]# B4 DSTBP [1]# Y5 RESET# D15 D [53]# E1 DSTBP [2]# K3 RS [0]# W18 D [54]# A5 DSTBP [3]# F3 RS [1]# Y17 D [55]# C3 FERR# T16 RS [2]# U20 D [56]# A6 FORCEPR# N15 AP#0 D17 D [57]# F2 GTLREF A7 DPSLP# R17 D [58]# C6 HIT# AA17 AP#1 M18 D [59]# B6 HITM# V20 BNT# T17 D [6]# AA16 IERR# F16 CMREF B7 D [60]# B3 IGNNE# J4 CORE_DET A13 D [61]# C4 INIT# V16 EDM R6 D [62]# C7 LINT0 T15 HPPLL N6 D [63]# D2 LINT1 R15 RSP# T6 D [7]# Y10 LOCK# W20 RSVD A3 D [8]# Y9 MCERR# P17 RSVD C1 D [9]# Y13 NC D6 RSVD C21 DBSY# Y18 NC G6 VCCPC61 E13 DCLKPH V5 NC H6 VCCPC62 E14 37 Package Mechanical Specifications and Pin Information 38 Signal Name Ball # Signal Name Ball # Signal Name Ball # VCCPC63 F13 VCC F11 VCCQ0 A9 VCCPC64 F14 VCC F12 VCCQ0 B9 SLP# N18 VCC G10 VCCSENSE C13 SMI# U17 VCC G11 VID [0] F15 STPCLK# R16 VCC G12 VID [1] D16 TCK M17 VCC H10 VID [2] E18 TDI N16 VCC H11 VID [3] G15 TDO M16 VCC H12 VID [4] G16 EXTREF M6 VCC J10 VID [5] E17 THERMTRIP# H17 VCC J11 VID [6] G18 THRMDA E4 VCC J12 VSS A2 THRMDC E5 VCC K10 VSS A4 TMS L17 VCC K11 VSS A8 TRDY# W19 VCC K12 VSS A15 TRST# K16 VCC L10 VSS A18 VCC A10 VCC L11 VSS A19 VCC A11 VCC L12 VSS A20 VCC A12 VCC M10 VSS B1 VCC B10 VCC M11 VSS B2 VCC B11 VCC M12 VSS B5 VCC B12 VCC N10 VSS B8 VCC C10 VCC N11 VSS B13 VCC C11 VCC N12 VSS B20 VCC C12 VCC P10 VSS B21 VCC D10 VCC P11 VSS C8 VCC D11 VCC P12 VSS C17 VCC D12 VCC R10 VSS D1 VCC E10 VCC R11 VSS D5 VCC E11 VCC R12 VSS D8 VCC E12 VCCA D7 VSS D14 VCC F10 VCCF V10 VSS D18 Datasheet Package Mechanical Specifications and Pin Information Datasheet Signal Name Ball # Signal Name Ball # Signal Name Ball # VSS D21 VSS J13 VSS P3 VSS E3 VSS J17 VSS P4 VSS E6 VSS K1 VSS P5 VSS E7 VSS K6 VSS P6 VSS E8 VSS K7 VSS P7 VSS E15 VSS K9 VSS P9 VSS E16 VSS K13 VSS P13 VSS E19 VSS K15 VSS P15 VSS F4 VSS K21 VSS P16 VSS F5 VSS L3 VSS P18 VSS F6 VSS L4 VSS P19 VSS F7 VSS L5 VSS R1 VSS F17 VSS L6 VSS R5 VSS F18 VSS L7 VSS R7 VSS G1 VSS L9 VSS R9 VSS G4 VSS L13 VSS R13 VSS G7 VSS L15 VSS R21 VSS G9 VSS L18 VSS T4 VSS G13 VSS L19 VSS T5 VSS G21 VSS M1 VSS T7 VSS H3 VSS M5 VSS T9 VSS H4 VSS M7 VSS T10 VSS H7 VSS M9 VSS T11 VSS H9 VSS M13 VSS T12 VSS H13 VSS M21 VSS T13 VSS H16 VSS N4 VSS T18 VSS H18 VSS N5 VSS U3 VSS H19 VSS N7 VSS U6 VSS J5 VSS N9 VSS U7 VSS J7 VSS N13 VSS U15 VSS J9 VSS N17 VSS U16 39 Package Mechanical Specifications and Pin Information 40 Signal Name Ball # Signal Name Ball # Signal Name Ball # VSS U19 VSS AA4 VTT L14 VSS V1 VSS AA7 VTT M8 VSS V4 VSS AA10 VTT M14 VSS V6 VSS AA12 VTT N8 VSS V7 VSS AA15 VTT N14 VSS V8 VSS AA18 VTT P8 VSS V13 VSS AA19 VTT P14 VSS V14 VSS AA20 VTT R8 VSS V18 VSSSENSE D13 VTT R14 VSS V21 VTT C9 VTT T8 VSS W1 VTT D9 VTT T14 VSS W5 VTT E9 VTT U8 VSS W8 VTT F8 VTT U9 VSS W11 VTT F9 VTT U10 VSS W14 VTT G8 VTT U11 VSS W17 VTT G14 VTT U12 VSS W21 VTT H8 VTT U13 VSS Y1 VTT H14 VTT U14 VSS Y2 VTT J8 DP#0 V9 VSS Y20 VTT J14 DP#1 R4 VSS Y21 VTT K8 DP#2 M4 VSS AA2 VTT K14 DP#3 D4 VSS AA3 VTT L8 Datasheet Package Mechanical Specifications and Pin Information 4.3 Signal Description Table 13. Signal Description Signal Name Type Description A [31:3]# (Address) defines a 232-byte physical memory address space. In sub-phase 1 of the address phase, these pins transmit the address of a transaction. A [31:3]# A20M# I/O I In sub-phase 2, these pins transmit transaction type information. These signals must connect the appropriate pins of both agents on the processor FSB. A [31:3]# are source synchronous signals and are latched into the receiving buffers by ADSTB [1:0]#. Address signals are used as straps which are sampled before RESET# is de-asserted. 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# ADSTB [1:0]# BCLK [1:0] I/O I/O I ADS# (Address Strobe) is asserted to indicate the validity of the transaction address on the A [31:3]# and REQ [4:0]# pins. All bus agents observe the ADS# activation to begin parity checking, protocol checking, address decode, internal loop, or deferred reply ID match operations associated with the new transaction. Address strobes are used to latch A [31:3]# and REQ [4:0]# on their rising and falling edges. Strobes are associated with signals as shown below. Signals REQ [4:0]#, A [16:3]# A [31:17]# Associated Strobe ADSTB [0]# ADSTB [1]# The differential pair BCLK (Bus Clock) determines the FSB frequency. All 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 VCROSS. BNR# Datasheet I/O BNR# (Block Next Request) is used to assert a bus stall by any bus agent who is unable to accept new bus transactions. During a bus stall, the current bus owner cannot issue any new transactions. 41 Package Mechanical Specifications and Pin Information Signal Name Type Description BPM [0]# O BPM [1]# I/O BPM [2]# O BPM [3]# I/O BPM [3:0]# (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 [3:0]# should connect the appropriate pins of all FSB agents. This includes debug or performance monitoring tools. BPRI# I BPRI# (Bus Priority Request) is used to arbitrate for ownership of the FSB. It must connect the appropriate pins of both FSB agents. Observing BPRI# active (as asserted by the priority agent) causes the other agent 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# I/O BR0# is used by the processor to request the bus. The arbitration is done between the processor (Symmetric Agent) and Intel 945GSE (High Priority Agent). BSEL [2:0] O BSEL [2:0] (Bus Select) are used to select the processor input clock frequency. Table 4 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 Intel® Atom™ processor N270, the BSEL is fixed to operat at 133-MHz BCLK frequency. COMP [3:0] PWR COMP [3:0] must be terminated on the system board using precision (1% tolerance) resistors. D [63:0]# (Data) are the data signals. These signals provide a 64-bit data path between the FSB agents, and must connect the appropriate pins on both 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 DINV#. D [63:0]# I/O Quad-Pumped Signal Groups Data Group DSTBN#/DSTBP# DINV# D [15:0]# 0 0 D [31:16]# 1 1 D [47:32]# 2 2 D [63:48]# 3 3 Furthermore, the DINV# pins determine the polarity of the data signals. Each group of 16 data signals corresponds to one DINV# signal. When the DINV# signal is active, the corresponding data group is inverted and therefore sampled active high. 42 Datasheet Package Mechanical Specifications and Pin Information Signal Name DBSY# DEFER# Type Description I/O DBSY# (Data Bus Busy) is asserted by the agent responsible for driving data on the 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 on both FSB agents. I 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 of both FSB agents. DINV [3:0]# (Data Bus Inversion) are source synchronous and indicate the polarity of the D [63:0]# signals. The DINV [3:0]# signals are activated when the data on the data bus is inverted. The bus agent will invert the data bus signals if more than half the bits, within the covered group, would change level in the next cycle. DINV [3:0]# assignment to data bus signals is shown below. DINV [3:0]# I Bus Signal Data Bus Signals DINV [3]# D [63:48]# DINV [2]# D [47:32]# DINV [1]# D [31:16]# DINV [0]# D [15:0]# I DPRSTP# when asserted on the platform causes the processor to transition from the Deep Sleep State to the Deeper Sleep state. In order to return to the Deep Sleep State, DPRSTP# must be deasserted. DPRSTP# is driven by the South Bridge chipset. DPSLP# I DPSLP# when asserted on the platform causes the processor to transition from the Sleep State to the Deep Sleep state. In order to return to the Sleep State, DPSLP# must be de-asserted. DPSLP# is driven by the South Bridge chipset. DPWR# I DPWR# is a control signal from the Intel 945GSE chipset used to reduce power on the processor data bus input buffers. I/O DRDY# (Data Ready) is asserted by the data driver on each data transfer, indicating valid data on the data bus. In a multicommon clock data transfer, DRDY# may be de-asserted to insert idle clocks. This signal must connect the appropriate pins of both FSB agents. DPRSTP# DRDY# Data strobe used to latch in D [63:0]# DSTBN [3:0]# Datasheet I/O Signals Associated Strobe D [15:0]# DINV [0]#, DSTBN [0]# D [31:16]# DINV [1]#, DSTBN [1]# D [47:32]# DINV [2]#, DSTBN [2]# D [63:48]# DINV [3]#, DSTBN [3]# 43 Package Mechanical Specifications and Pin Information Signal Name Type Description Data strobe used to latch in D [63:0]#. DSTBP [3:0]# FERR#/PBE# I/O O Signals Associated Strobe D [15:0]# DINV [0]#, DSTBP [0]# D [31:16]# DINV [1]#, DSTBP [1]# D [47:32]# DINV [2]#, DSTBP [2]# D [63:48]# DINV [3]#, DSTBP [3]# FERR# (Floating-point Error)PBE#(Pending Break Event) is a multiplexed signal and its meaning is qualified with STPCLK#. When STPCLK# is not asserted, FERR#/PBE# indicates a floating point when the processor detects an unmasked floating-point error. FERR# is similar to the ERROR# signal on the Intel 387 coprocessor, and is included for compatibility with systems using MSDOS*- 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. When FERR#/PBE# is asserted, indicating a break event, it will remain asserted until STPCLK# is de-asserted. Assertion of PREQ# when STPCLK# is active will also cause an FERR# break event. For additional information on the pending break event functionality, including identification of support of the feature and enable/disable information, refer to Volume 3 of the Intel® 64 and IA-32 Architectures Software Developer's Manuals and the Intel® Processor Identification and CPUID Instruction Application Note. For termination requirements please contact your Intel representative. CMREF PWR CMREF determines the signal reference level for CMOS input pins. CMREF should be set at 1/2 VCCP. CMREF is used by the CMOS receivers to determine if a signal is a logical-0 or logical-1. NOTE: Because of not using CMOS, CMREF and GTLREF should be provided with 2/3 VCCP. 44 GTLREF PWR HIT# HITM# I/O GTLREF determines the signal reference level for AGTL+ input pins. GTLREF should be set at 2/3 VCCP. GTLREF is used by the AGTL+ receivers to determine if a signal is a logical-0 or logical1. HIT# (Snoop Hit) and HITM# (Hit Modified) convey transaction snoop operation results. Either 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. Datasheet Package Mechanical Specifications and Pin Information Signal Name IERR# IGNNE# Type Description O 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 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#, BINIT#, or INIT#. I IGNNE# (Ignore Numeric Error) is asserted to force the processor to ignore a numeric error and continue to execute non-control floating-point instructions. If IGNNE# is de-asserted, the processor generates an exception on a non-control 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# I 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. 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# must connect the appropriate pins of both FSB agents. If INIT# is sampled active on the active to inactive transition of RESET#, the processor reverses its FSB data and address signals internally to ease motherboard layout for systems where the chipset is on the other side of the motherboard. D [63:0] => D [0:63] A [31:3] => A [3:31] DINV [3:0]# is also reversed. LINT [1:0] I LINT [1:0] (Local APIC Interrupt) must connect the appropriate pins 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 non-maskable 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 pins as LINT [1:0] is the default configuration. Datasheet 45 Package Mechanical Specifications and Pin Information Signal Name Type Description Lock# indicates to the system that a transaction must occur atomically. This signal must connect the appropriate pins of both 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. LOCK# I/O PRDY# O Probe Ready signal used by debug tools to request debug operation of the processor. Please contact your Intel representative for more implementation details. PREQ# I Probe Request signal used by debug tools to request debug operation of the processor. Please contact your Intel representative for more implementation details. PROCHOT# I/O, O (DP) When the priority agent asserts BPRI# to arbitrate for ownership of the FSB, it will wait until it observes LOCK# deasserted. This enables symmetric agents to retain ownership of the FSB throughout the bus locked operation and ensure the atomicity of lock. As an output, PROCHOT# (Processor Hot) will go active when the processor temperature monitoring sensor detects that the processor has reached its 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#. This signal may require voltage translation on the motherboard. Please contact your Intel representative for more implementation details. PWRGOOD I 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. It must also meet the minimum pulse width specification, and be followed by a 2-ms (minimum) RESET# pulse. 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. For termination requirements, please contact your Intel representative for more implementation details. REQ [4:0]# 46 I/O REQ [4:0]# (Request Command) must connect the appropriate pins of both FSB agents. They are asserted by the current bus owner to define the currently active transaction type. These signals are source synchronous to ADSTB [0] #. Datasheet Package Mechanical Specifications and Pin Information Signal Name RESET# Type I Description 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 two milliseconds after VCC and BCLK have reached their proper specifications. On observing active RESET#, both FSB agents will de-assert their outputs within two clocks. All processor straps must be valid within the specified setup time before RESET# is de-asserted. Please contact your Intel representative for more implementation details. RS [2:0]# RSVD Reserved 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 of both FSB agents. All other RSVD signals can be left as No Connects. I SLP# (Sleep), when asserted in Stop-Grant state, causes the processor to enter the Sleep state. During Sleep state, the processor stops providing internal clock signals to all units, leaving only the Phase-Locked Loop (PLL) still operating. Processors in this state will not recognize snoops or interrupts. The processor will recognize only assertion of the RESET# signal, de-assertion of SLP#, and removal of the BCLK input while in Sleep state. If SLP# is de-asserted, the processor exits Sleep state and returns to Stop-Grant state, restarting its internal clock signals to the bus and processor core units. If DPSLP# is asserted while in the Sleep state, the processor will exit the Sleep state and transition to the Deep Sleep state. I SMI# (System Management Interrupt) is asserted asynchronously by system logic. On accepting a System Management Interrupt, the processor saves the current state and enters 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 tri-state its outputs. STPCLK# I STPCLK# (Stop Clock), when asserted, causes the processor to enter a low power Stop-Grant state. The processor issues a StopGrant Acknowledge transaction, and stops providing internal clock signals to all processor core units 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 I TCK (Test Clock) provides the clock input for the processor Test Bus (also known as the Test Access Port). Please contact your Intel representative for more implementation details. I TDI (Test Data In) transfers serial test data into the processor. TDI provides the serial input needed for JTAG specification support. Please contact your Intel representative for more implementation details. SLP# SMI# TDI Datasheet I 47 Package Mechanical Specifications and Pin Information Signal Name TDO Description O TDO (Test Data Out) transfers serial test data out of the processor. TDO provides the serial output needed for JTAG specification support. Please contact your Intel representative for more implementation details. TEST[1:4] Refer to the appropriate platform design guide for further TEST1, TEST2, TEST3, and TEST4 termination requirements and implementation details. All TEST signals can be left as No Connects. THRMTRIP# The processor protects itself from catastrophic overheating by use of an internal thermal sensor. This sensor is set well above the normal operating temperature to ensure that there are no false trips. The processor will stop all execution when the junction temperature exceeds approximately 125°C. This condition is signaled to the system by the THERMTRIP# (Thermal Trip) pin. For termination requirements, please contact your Intel representative for more implementation details. O THRMDA PWR Thermal Diode - Anode THRMDC PWR Thermal Diode - Cathode TMS I TMS (Test Mode Select) is a JTAG specification support signal used by debug tools. Please contact your Intel representative for more implementation details. TRDY# I 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 of both FSB agents. TRST# I TRST# (Test Reset) resets the Test Access Port (TAP) logic. TRST# must be driven low during power on Reset. Please contact your Intel representative for more implementation details. VCCA PWR VCCA provides isolated power for the internal processor core PLLs. Please contact your Intel representative for more implementation details. VCC PWR Processor core power supply VSS GND Processor core ground node. VSS / NCTF GND Non Critical to Function VID [6:0] VCCP 48 Type O PWR VID [6:0] (Voltage ID) pins are used to support automatic selection of power supply voltages (VCC). Unlike some previous generations of processors, these are CMOS signals that are driven by the processor. The voltage supply for these pins must be valid before the VR can supply VCC to the processor. Conversely, the VR output must be disabled until the voltage supply for the VID pins becomes valid. The VID pins are needed to support the processor voltage specification variations. See Table 3 for definitions of these pins. The VR must supply the voltage that is requested by the pins, or disable itself. Processor I/O Power Supply Datasheet Package Mechanical Specifications and Pin Information Signal Name VCC_SENSE VSS_SENSE Type Description O VCCSENSE is an isolated low impedance connection to processor core power (VCC). It can be used to sense or measure power near the silicon with little noise. Please contact your Intel representative for more implementation details. O VSS_SENSE is an isolated low impedance connection to processor core VSS. It can be used to sense or measure ground near the silicon with little noise. Please contact your Intel representative for more implementation details. § Datasheet 49 Thermal Specifications and Design Considerations 5 Thermal Specifications and Design Considerations The processor requires a thermal solution to maintain temperatures within operating limits. A complete thermal solution includes both component and system level thermal management features. The system/processor thermal solution should be designed such that the processor remains within the minimum and maximum junction temperature (TJ) specifications at the corresponding thermal design power (TDP) value listed in Table 14 through Table 16. Thermal solutions not designed to provide this level of thermal capability may affect the long-term reliability of the processor and system. Attempts to operate the processor outside these operating limits may result in permanent damage to the processor and potentially other components in the system. Table 14. Power Specifications for the Processor Symbol Processor Number Core Frequency and Voltage Thermal Design Power Unit TDP N270 1.6 GHz HFM VCC 2.5W W Symbol PAH, PSGNT PDSLP PDPRSLP TJ Parameter Min Typ Max Unit — — 1.0 W 0.7 W Auto Halt, Stop Grant Power at HFM VCC at LFM VCC Deep Sleep Power — — 0.5 W Deeper Sleep Power — — 0.5 W Junction Temperature 0 — 90 °C Notes At 90°C 1, 4 Notes At 70°C 2 At 50°C 2, 5 At 50°C 2, 5 3, 4 NOTES: 1. The TDP specification should be used to design the processor thermal solution. The TDP is not the maximum theoretical power the processor can generate. 2. Not 100% tested. These power specifications are determined by characterization of the processor currents at higher temperatures and extrapolating the values for the temperature indicated. 3. As measured by the activation of the on-die Intel Thermal Monitor. The Intel Thermal Monitor’s automatic mode is used to indicate that the maximum TJ has been reached. Refer to Section Error! Reference source not found. for more details. 4. The Intel Thermal Monitor automatic mode must be enabled for the processor to operate within specifications. 5. Deep Sleep state is mapped to Deeper Sleep State. 50 Datasheet Thermal Specifications and Design Considerations The processor incorporates three methods of monitoring die temperature: the Digital Thermal Sensor, Intel Thermal Monitor, and the Thermal Diode. The Intel Thermal Monitor (detailed in Section 5.2) must be used to determine when the maximum specified processor junction temperature has been reached. 5.1 Thermal Diode The processor incorporates an on-die PNP transistor whose base emitter junction is used as a thermal “diode”, with its collector shorted to ground. The thermal diode can be read by an off-die analog/digital converter (a thermal sensor) located on the motherboard or a stand-alone measurement kit. The thermal diode may be used to monitor the die temperature of the processor for thermal management or instrumentation purposes but is not a reliable indication that the maximum operating temperature of the processor has been reached. When using the thermal diode, a temperature offset value must be read from a processor MSR and applied. See Section 5.2 for more details. See Section 5.3 for thermal diode usage recommendation when the PROCHOT# signal is not asserted. The reading of the external thermal sensor (on the motherboard) connected to the processor thermal diode signals will not necessarily reflect the temperature of the hottest location on the die. This is due to inaccuracies in the external thermal sensor, on-die temperature gradients between the location of the thermal diode and the hottest location on the die, and time based variations in the die temperature measurement. Time based variations can occur when the sampling rate of the thermal diode (by the thermal sensor) is slower than the rate at which the TJ temperature can change. Offset between the thermal diode based temperature reading and the Intel Thermal Monitor reading may be characterized using the Intel Thermal Monitor’s Automatic mode activation of the thermal control circuit. This temperature offset must be taken into account when using the processor thermal diode to implement power management events. This offset is different than the diode Toffset value programmed into the processor Model Specific Register (MSR). Table 15 and Table 16 provide the diode interface and specifications. Transistor model parameters shown in Table 16 provide more accurate temperature measurements when the diode ideality factor is closer to the maximum or minimum limits. Contact your external sensor supplier for their recommendation. The thermal diode is separate from the Thermal Monitor’s thermal sensor and cannot be used to predict the behavior of the Thermal Monitor. Datasheet 51 Thermal Specifications and Design Considerations Table 15. Thermal Diode Interface Signal Name Pin/Ball Number Signal Description THERMDA E4 Thermal diode anode THERMDC E5 Thermal diode cathode Table 16. Thermal Diode Parameters using Transistor Model Symbol Min Typ Max Unit Notes Forward Bias Current 5 — 200 μA 1 IE Emitter Current 5 — 200 μA 1 nQ Transistor Ideality 0.997 1.001 1.015 2,3,4 0.25 — 0.65 2,3 2.79 4.52 6.24 IFW Parameter Beta RT Series Resistance Ω 2,5 NOTES: 1. Intel does not support or recommend operation of the thermal diode under reverse bias. 2. Characterized across a temperature range of 50–100°C. 3. Not 100% tested. Specified by design characterization. 4. The ideality factor, nQ, represents the deviation from ideal transistor model behavior as exemplified by the equation for the collector current: IC = IS * (e qVBE/nQkT –1) where IS = saturation current, q = electronic charge, VBE = voltage across the transistor base emitter junction (same nodes as VD), k = Boltzmann Constant, and T = absolute temperature (Kelvin). 5. The series resistance, RT, provided in the Diode Model Table (Table 16) can be used for more accurate readings as needed. When calculating a temperature based on the thermal diode measurements, a number of parameters must be either measured or assumed. Most devices measure the diode ideality and assume a series resistance and ideality trim value, although are capable of also measuring the series resistance. Calculating the temperature is then accomplished using the equation listed under Table 16. In most sensing devices, an expected value for the diode ideality is designed-in to the temperature calculation equation. If the designer of the temperature sensing device assumes a perfect diode, the ideality value (also called ntrim) will be 1.000. Given that most diodes are not perfect, the designers usually select an ntrim value that more closely matches the behavior of the diodes in the processor. If the processor diode ideality deviates from that of the ntrim, each calculated temperature will be offset by a fixed amount. This temperature offset can be calculated with the equation: Terror(nf) = Tmeasured * (1 – nactual/ntrim) Where Terror(nf) is the offset in degrees C, Tmeasured is in Kelvin, nactual is the measured ideality of the diode, and ntrim is the diode ideality assumed by the temperature sensing device. 52 Datasheet Thermal Specifications and Design Considerations 5.2 Intel® Thermal Monitor The Intel Thermal Monitor helps control the processor temperature by activating the TCC (Thermal Control Circuit) when the processor silicon reaches its maximum operating temperature. The temperature at which the Intel Thermal Monitor activates the TCC is not user configurable. 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. 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 minor and hence not detectable. An underdesigned 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 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. The Intel Thermal Monitor controls the processor temperature by modulating (starting and stopping) the processor core clocks or by initiating an Enhanced Intel SpeedStep Technology transition when the processor silicon reaches its maximum operating temperature. The Intel Thermal Monitor uses two modes to activate the TCC: automatic mode and on-demand mode. If both modes are activated, automatic mode takes precedence. There are two automatic modes called Intel Thermal Monitor-1 and Intel Thermal Monitor-2. These modes are selected by writing values to the MSRs of the processor. After automatic mode is enabled, the TCC will activate only when the internal die temperature reaches the maximum allowed value for operation. The Intel Thermal Monitor automatic mode must be enabled through BIOS for the processor to be operating within specifications. Intel recommends Intel Thermal Monitor-1 and Intel Thermal Monitor-2 be enabled on the processor. When Intel Thermal Monitor-1 is enabled and a high temperature situation exists, the clocks will be modulated by alternately turning the clocks off and on at a 50% duty cycle. Cycle times are processor speed dependent and will decrease linearly as processor core frequencies increase. Once the temperature has returned to a noncritical level, modulation ceases and TCC goes inactive. A small amount of hysteresis has been included to prevent rapid active/inactive transitions of the TCC when the processor temperature is near the trip point. The duty cycle is factory configured and cannot be modified. Also, automatic mode does not require any additional hardware, software drivers, or interrupt handling routines. Processor performance will be decreased by the same amount as the duty cycle when the TCC is active. When Intel Thermal Monitor-2 is enabled and a high temperature situation exists, the processor will perform an Enhanced Intel SpeedStep Technology transition to the LFM. When the processor temperature drops below the critical level, the processor will make an Enhanced Intel SpeedStep Technology transition to the last requested operating point. The processor also supports Enhanced Multi Threaded Thermal Monitoring (EMTTM). EMTTM is a processor feature that enhances Intel Thermal Monitor-2 with a processor throttling algorithm known as Adaptive Intel Thermal Monitor-2. Adaptive Intel Thermal Monitor-2 transitions to intermediate operating points, rather than directly to the LFM, once the processor has reached its thermal Datasheet 53 Thermal Specifications and Design Considerations limit and subsequently searches for the highest possible operating point. Please ensure this feature is enabled and supported in the BIOS. Also with EMTTM enabled, the operating system can request the processor to throttling to any point between Intel Dynamic Acceleration frequency and Super LFM frequency as long as these features are enabled in the BIOS and supported by the processor. The Intel Thermal Monitor automatic mode and Enhanced Multi Threaded Thermal Monitoring must be enabled through BIOS for the processor to be operating within specifications. Intel recommends Intel Thermal Monitor-1 and Intel Thermal Monitor-2 be enabled on the processors. Intel Thermal Monitor-1, Intel Thermal Monitor-2, and EMTTM features are collectively referred to as Adaptive Thermal Monitoring features. Intel Thermal Monitor-1 and Intel Thermal Monitor-2 can co-exist within the processor. If both Intel Thermal Monitor-1 and Intel Thermal Monitor-2 bits are enabled in the auto-throttle MSR, Intel Thermal Monitor-2 will take precedence over Intel Thermal Monitor-1. However, if Force Intel Thermal Monitor-1 over Intel Thermal Monitor-2 is enabled in MSRs via BIOS and Intel Thermal Monitor-2 is not sufficient to cool the processor below the maximum operating temperature, then Intel Thermal Monitor-1 will also activate to help cool down the processor. If a processor load based Enhanced Intel SpeedStep Technology transition (through MSR write) is initiated when a Intel Thermal Monitor-2 period is active, there are two possible results: • If the processor load based Enhanced Intel SpeedStep technology transition target frequency is higher than the Intel Thermal Monitor-2 transition based target frequency, the processor load-based transition will be deferred until the Intel Thermal Monitor-2 event has been completed. • If the processor load-based Enhanced Intel SpeedStep technology transition target frequency is lower than the Intel Thermal Monitor-2 transition based target frequency, the processor will transition to the processor load-based Enhanced Intel SpeedStep technology target frequency point. The TCC may also be activated via on-demand mode. If bit 4 of the ACPI Intel Thermal Monitor control register is written to a 1, the TCC will be activated immediately independent of the processor temperature. When using on-demand mode to activate the TCC, the duty cycle of the clock modulation is programmable via bits 3:1 of the same ACPI Intel Thermal Monitor control register. In automatic mode, the duty cycle is fixed at 50% on, 50% off, however 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 at the same time automatic mode is enabled; however, if the system tries to enable the TCC via on-demand mode at the same time automatic mode is enabled and a high temperature condition exists, automatic mode will take precedence. An external signal, PROCHOT# (processor hot) is asserted when the processor detects that its temperature is above the thermal trip point. Bus snooping and interrupt latching are also active while the TCC is active. Besides the thermal sensor and thermal control circuit, the Intel Thermal Monitor also includes one ACPI register, one performance counter register, three MSR, and one I/O pin (PROCHOT#). All are available to monitor and control the state of the Intel 54 Datasheet Thermal Specifications and Design Considerations Thermal Monitor feature. The Intel Thermal Monitor can be configured to generate an interrupt upon the assertion or de-assertion of PROCHOT#. PROCHOT# will not be asserted when the processor is in the Stop Grant, Sleep, Deep Sleep, and Deeper Sleep low power states; hence, the thermal diode reading must be used as a safeguard to maintain the processor junction temperature within maximum specification. If the platform thermal solution is not able to maintain the processor junction temperature within the maximum specification, the system must initiate an orderly shutdown to prevent damage. If the processor enters one of the above low power states with PROCHOT# already asserted, PROCHOT# will remain asserted until the processor exits the low power state and the processor junction temperature drops below the thermal trip point. If Intel Thermal Monitor automatic mode is disabled, the processor will be operating out of specification. Regardless of enabling the automatic or on-demand modes, in the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon has reached a temperature of approximately 125°C. At this point the THERMTRIP# signal will go active. THERMTRIP# activation is independent of processor activity and does not generate any bus cycles. When THERMTRIP# is asserted, the processor core voltage must be shut down within the time specified in Chapter 3. 5.3 Digital Thermal Sensor The processor also contains an on-die Digital Thermal Sensor (DTS) that is read via an MSR (no I/O interface). The DTS is only valid while the processor is in the normal operating state (the Normal package level low power state). Unlike traditional thermal devices, the DTS outputs a temperature relative to the maximum supported operating temperature of the processor (TJ_max). It is the responsibility of software to convert the relative temperature to an absolute temperature. The temperature returned by the DTS will always be at or below TJ_max. Catastrophic temperature conditions are detectable via an Out Of Spec status bit. This bit is also part of the DTS MSR. When this bit is set, the processor is operating out of specification and immediate shutdown of the system should occur. The processor operation and code execution is not ensured once the activation of the “Out of Spec” status bit is set. The DTS-relative temperature readout corresponds to the Intel Thermal Monitor-1 and Intel Thermal Monitor -2 trigger point. When the DTS indicates maximum processor core temperature has been reached, the Intel Thermal Monitor-1 or Intel Thermal Monitor-2 hardware thermal control mechanism will activate. The DTS and Intel Thermal Monitor-1/Intel Thermal Monitor-2 temperature may not correspond to the thermal diode reading since the thermal diode is located in a separate portion of the die and thermal gradient between the individual core DTS. Additionally, the thermal gradient from DTS to thermal diode can vary substantially due to changes in processor power, mechanical and thermal attach, and software application. The system designer is required to use the DTS to ensure proper operation of the processor within its temperature operating specifications. Changes to the temperature can be detected via two programmable thresholds located in the processor MSRs. These thresholds have the capability of generating interrupts via the core's local APIC. Datasheet 55 Thermal Specifications and Design Considerations Note: The digital thermal sensor (DTS) accuracy is in the order of -5°C ~ +10°C around 90°C; it deteriorates to ±10°C at 50°C. The DTS temperature reading saturates at some temperature below 50°C. Any DTS reading below 50°C should be considered to indicate only a temperature below 50°C and not a specific temperature. External thermal sensor with “BJT” model is required to read thermal diode temperature. 5.3.1 Out of Specification Detection Overheat detection is performed by monitoring the processor temperature and temperature gradient. This feature is intended for graceful shut down before the THERMTRIP# is activated. If the processor’s Intel Thermal Monitor-1 or Intel Thermal Monitor-2 are triggered and the temperature remains high, an “Out Of Spec” status and sticky bit are latched in the status MSR register and generates thermal interrupt. 5.3.2 PROCHOT# Signal Pin An external signal, PROCHOT# (processor hot), is asserted when the processor die temperature has reached its maximum operating temperature. If Intel Thermal Monitor-1 or Intel Thermal Monitor-2 is enabled, then 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#. The processor implements a bi-directional PROCHOT# capability to allow system designs to protect various components from overheating 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. Only a single PROCHOT# pin exists at a package level of the processor. When the core's thermal sensor trips, the PROCHOT# signal will be driven by the processor package. If only Intel Thermal Monitor-1 is enabled, PROCHOT# will be asserted and only the core that is above TCC temperature trip point will have its core clocks modulated. If Intel Thermal Monitor-2 is enabled and the core is above TCC temperature trip point, it will enter the lowest programmed Intel Thermal Monitor-2 performance state. It is important to note that Intel recommends both Intel Thermal Monitor-1 and Intel Thermal Monitor-2 to be enabled. When PROCHOT# is driven by an external agent and if only Intel Thermal Monitor-1 is enabled on the core, then the processor core will have the clocks modulated. If Intel Thermal Monitor-2 is enabled, then the processor core will enter the lowest programmed Intel Thermal Monitor-2 performance state. It should be noted that Force Intel Thermal Monitor-1 on Intel Thermal Monitor-2, enabled via BIOS, does not have any effect on external PROCHOT#. If PROCHOT# is driven by an external agent when Intel Thermal Monitor-1, Intel Thermal Monitor-2, and Force Intel Thermal Monitor-1 on Intel Thermal Monitor-2 are all enabled, then the processor will still apply only Intel Thermal Monitor-2. PROCHOT# may be used for 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 will cool down as a result of reduced processor power 56 Datasheet Thermal Specifications and Design Considerations consumption. Bi-directional PROCHOT# can allow VR thermal designs to target maximum sustained current 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 TDP. 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. § Datasheet 57