Intel Xeon Guide

Intel®Xeon™ Processor with
512 KB L2 Cache and Intel®
E7500 Chipset Platform
Design Guide
March 2002
Document Number: 298649-002

Design Guide 2
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Copyright © 2002, Intel Corporation

Design Guide 3
Contents
1 Introduction................................................................................................................15
1.1 Reference Documentation...................................................................................15
1.2 Conventions and Terminology.............................................................................17
1.3 System Overview ................................................................................................19
1.3.1 Intel® Xeon™ Processor with 512 KB L2 Cache ...............................20
1.3.2 Intel® E7500 Chipset .........................................................................21
1.3.2.1 Intel® E7500 Memory Controller Hub (MCH).......................21
1.3.2.2 I/O Controller Hub 3 (Intel®ICH3-S).....................................22
1.3.2.3 PCI/PCI-X 64-bit Hub 2 (Intel®82870P2 P64H2).................22
1.3.3 Bandwidth Summary ..........................................................................23
1.3.4 System Configurations .......................................................................23
2 Component Quadrant Layout..............................................................................25
2.1 Intel® Xeon™ Processor with 512 KB L2 Cache Quadrant Layout ....................26
2.2 Intel® E7500 MCH Quadrant Layout...................................................................27
2.3 Intel®ICH3-S Quadrant Layout...........................................................................28
2.4 Intel®82870P2 P64H2 Quadrant Layout ............................................................29
3 Platform Stack-Up and Component Placement Overview.......................31
3.1 Platform Component Placement .........................................................................31
3.2 Platform Stack-Up ...............................................................................................32
4 Platform Clock Routing Guidelines..................................................................35
4.1 Clock Groups.......................................................................................................38
4.1.1 HOST_CLK Clock Group ...................................................................38
4.1.1.1 HOST_CLK Clock Topology.................................................38
4.1.1.2 HOST_CLK General Routing Guidelines..............................41
4.1.1.3 CK408 vs. CK408B Requirement.........................................41
4.1.2 CLK66 Clock Group ...........................................................................42
4.1.2.1 CLK66 Skew Requirements..................................................43
4.1.3 CLK33_ICH3-S Clock.........................................................................45
4.1.4 CLK33 Clock Group ...........................................................................46
4.1.5 CLK14 Clock Group ...........................................................................48
4.1.6 USBCLK Clock Group........................................................................49
4.2 Clock Driver Decoupling......................................................................................50
4.3 Clock Driver Power Delivery................................................................................51
4.4 EMI Constraints...................................................................................................51
5 System Bus Routing Guidelines........................................................................53
5.1 Routing Guidelines for the AGTL+ Source Synchronous 2X and 4X Groups .....56
5.1.1 Trace Length Matching.......................................................................56
5.2 Routing Guidelines for Common Clock Signals ..................................................58
5.2.1 Wired-OR Signals...............................................................................58
5.2.2 RESET# Topology..............................................................................59
5.3 Routing Guidelines for Asynchronous GTL+ and Miscellaneous Signals ...........59
5.3.1 Asynchronous GTL+ Signals Driven by the Processor ......................60
5.3.1.1 Proper THERMTRIP# Usage................................................61

4Design Guide
5.3.2 Asynchronous GTL+ Signals Driven by the Chipset ..........................61
5.3.2.1 Proper Power Good Usage ..................................................62
5.3.2.2 Voltage Translation for INIT#................................................62
5.3.3 VID[4:0] ..............................................................................................63
5.3.4 SMBus Signals...................................................................................63
5.3.5 System Bus COMP Routing Guidelines.............................................64
5.3.6 BR[3:0]# Routing Guidelines..............................................................64
5.3.7 ODTEN Signal Routing Guidelines ....................................................64
5.3.8 TESTHI[6:0] Routing Guidelines........................................................65
5.3.9 SKTOCC# Signal Routing Guidelines................................................65
6 Memory Interface Routing Guidelines.............................................................67
6.1 DDR Overview ....................................................................................................68
6.2 Source Synchronous Signal Group.....................................................................70
6.3 Command Clock Routing ....................................................................................73
6.4 Source Clocked Signal Group Routing ...............................................................75
6.5 Chip Select Routing ............................................................................................76
6.6 Clock Enable Routing..........................................................................................77
6.7 Enable Signal (RCVEN#)....................................................................................78
6.8 Miscellaneous Signals.........................................................................................79
6.9 DDR Reference Voltage......................................................................................80
6.10 DDR Signal Termination .....................................................................................81
6.11 Decoupling Requirements...................................................................................82
7 Hub Interface..............................................................................................................83
7.1 Signal Naming Convention..................................................................................83
7.2 Hub Interface 2.0 Implementation.......................................................................84
7.2.1 Hub Interface 2.0 High-Speed Routing Guidelines ............................84
7.2.2 Hub Interface 2.0 Generation/Distribution of Reference Voltages .....87
7.2.3 Hub Interface 2.0 Resistive Compensation........................................88
7.2.4 Hub Interface 2.0 Decoupling Guidelines...........................................89
7.2.5 Unused Hub Interface 2.0 Interfaces..................................................89
7.3 Hub Interface 1.5 Implementation.......................................................................89
7.3.1 Hub Interface 1.5 High-Speed Routing Guidelines ............................89
7.3.2 Hub Interface 1.5 Generation/Distribution of Reference Voltages .....90
7.3.3 Hub Interface 1.5 Resistive Compensation........................................91
7.3.4 Hub Interface 1.5 Decoupling Guidelines...........................................92
8Intel
®82870P2 (P64H2)..........................................................................................93
8.1 PCI/PCI-X Design Guidelines .............................................................................93
8.1.1 PCI/PCI-X Routing Requirements (No Hot Plug)...............................94
8.1.2 PCI/PCI-X Hot Plug Routing Requirements.......................................95
8.1.3 Clock Configuration............................................................................96
8.1.4 Loop Clock Configuration...................................................................97
8.1.5 IDSEL Implementation .......................................................................98
8.1.6 SMBus Address..................................................................................98
8.2 Hot Plug Implementation.....................................................................................99
8.2.1 Standard Usage Model.......................................................................99
8.2.1.1 Hot-Removals.......................................................................99
8.2.1.2 Hot-Insertions .....................................................................100
8.2.2 Hot Plug Switch Implementation ......................................................100

Design Guide 5
8.2.2.1 Manually-Operated Retention Latch Sensor.......................101
8.2.2.2 Optional Attention Button....................................................102
8.2.3 LED Indicator Outputs......................................................................102
8.2.4 Disabling/Enabling an Intel® P64H2 Hot Plug Controller..................103
8.2.4.1 Hot Plug Strapping Options ................................................103
8.2.4.2 Hot Plug Registers’ Visibility...............................................103
8.2.5 Single Slot Parallel Mode .................................................................103
8.2.5.1 Required Additional Logic...................................................103
8.2.5.2 PCI Clock............................................................................103
8.2.5.3 Debounced Hot Plug Switch Input......................................104
8.2.5.4 Comparator Circuit for PCIXCAP1/PCIXCAP2 Pins...........104
8.2.5.5 Tri-State Buffer or 2:1 MUX for HPxSLOT [2:0]..................104
8.2.5.6 Hot Plug Muxed Signals in Single Slot Parallel Mode ........105
8.2.5.7 SMBus Address Considerations.........................................106
8.2.5.8 Pull-Ups/Pull-Downs in Single Slot Parallel Mode..............106
8.2.5.9 Reference Schematic for Single-Slot Parallel Mode...........107
8.2.6 Dual Slot Parallel Mode....................................................................108
8.2.6.1 Required Additional Logic...................................................108
8.2.6.2 Debounced Hot Plug Switch Input......................................108
8.2.6.3 Comparator Circuit for PCIXCAP1/PCIXCAP2 Pins...........108
8.2.6.4 Tri-State Buffer or 2:1 Mux for HPxSLOT [2:0]...................108
8.2.6.5 HPx_SID Output Signal ......................................................108
8.2.6.6 Pull-Ups/Pull-Downs in Dual Slot Parallel Mode.................108
8.2.6.7 Hot Plug Muxed Signals in Dual Slot Parallel Mode...........109
8.2.6.8 SMBus Address Considerations.........................................110
8.2.6.9 Reference Schematic for Dual-Slot Parallel Mode .............111
8.2.7 Three or More Slot Serial Mode .......................................................112
8.2.7.1 Hot Plug and Non-Hot Plug Combinations .........................112
8.2.7.2 Required Additional Logic...................................................112
8.2.7.3 Debounced Hot Plug Switch Input......................................112
8.2.7.4 Comparator Circuit for PCIXCAP1/PCIXCAP2 Pins...........112
8.2.7.5 HPxSLOT [2:0]....................................................................112
8.2.7.6 Stutter Logic for Implementing Fewer Than Six Slots.........112
8.2.7.7 Pull-Ups/Pull-Downs in Three or More Slot Serial Mode....113
8.2.7.8 Reference Schematic for Serial Mode................................114
8.2.8 Intel® P64H2 PCI Interface PCIXCAP and M66EN Pins..................115
8.2.8.1 PCIXCAP Pin Requirements ..............................................115
8.2.8.2 M66EN Pin Requirements..................................................115
9 I/O Controller Hub..................................................................................................119
9.1 IDE Interface .....................................................................................................119
9.1.1 Cabling .............................................................................................119
9.1.2 Cable Detection for Ultra ATA/66 and Ultra ATA/100 ......................120
9.1.2.1 Combination Host-Side/Device-Side Cable Detection........120
9.1.3 Primary IDE Connector Requirements.............................................121
9.1.4 Secondary IDE Connector Requirements ........................................122
9.2 SPKR Pin Consideration...................................................................................123
9.3 PCI ....................................................................................................................123
9.4 USB...................................................................................................................124
9.4.1 General Routing and Placement ......................................................124
9.4.2 USB Trace Separation .....................................................................125
9.4.3 USB Trace Length Matching ............................................................125

6Design Guide
9.4.4 Plane Splits, Voids, and Cut-Outs (Anti-Etch)..................................125
9.4.4.1 VCC Plane Splits, Voids, and Cut-Outs (Anti-Etch)............125
9.4.4.2 GND Plane Splits, Voids, and Cut-Outs (Anti-Etch) ...........125
9.4.5 EMI Considerations..........................................................................125
9.4.6 USB Power Line Layout Topologies.................................................126
9.5 Intel®ICH3-S SMBus/SMLink Interface............................................................126
9.5.1 SMBus Design Considerations.........................................................127
9.5.2 General Design Note........................................................................127
9.5.3 The Unified VCC_CORE Architecture..............................................127
9.6 Real Time Clock (RTC).....................................................................................128
9.6.1 RTC External Circuit.........................................................................129
9.6.2 External Capacitors..........................................................................130
9.6.3 RTC Layout Considerations.............................................................131
9.6.4 RTC External Battery Connection....................................................131
9.6.5 RTC External RTCRST# Circuit.......................................................132
9.6.6 VBIAS DC Voltage and Noise Measurements .................................132
9.6.7 SUSCLK...........................................................................................133
9.6.8 RTC-Well Input Strap Requirements................................................133
9.7 Internal LAN Layout Guidelines ........................................................................133
9.7.1 LCI (LAN Connect Interface) Guidelines..........................................135
9.7.1.1 Bus Topology......................................................................135
9.7.1.2 Signal Routing and Layout .................................................136
9.7.1.3 Crosstalk Consideration .....................................................136
9.7.1.4 Impedances........................................................................136
9.7.1.5 Line Termination.................................................................136
9.7.2 General LAN Routing Guidelines and Considerations.....................137
9.7.2.1 General Trace Routing Considerations ..............................137
9.7.2.2 Trace Geometry and Length...............................................138
9.7.2.3 Signal Isolation ...................................................................138
9.7.2.4 Power and Ground Connections ........................................138
9.7.2.5 General Power and Ground Plane Consideration ..............139
9.7.2.6 Board Design......................................................................140
9.7.2.7 Common Physical Layout Issues .......................................140
9.7.3 Intel®82562ET/EM Guidelines ........................................................142
9.7.3.1 Guidelines for Intel®82562ET/EM Component Placement 142
9.7.3.2 Crystals and Oscillators......................................................142
9.7.3.3 Intel®82562ET/EM Termination Resistors.........................143
9.7.4 Critical Dimensions...........................................................................143
9.7.5 Terminating Unused Connections....................................................145
10 Debug Port................................................................................................................147
10.1 Logic Analyzer Interface (LAI)...........................................................................147
10.2 Mechanical Considerations...............................................................................147
10.3 Electrical Considerations...................................................................................147
11 EMI and Mechanical Design Considerations..............................................149
11.1 Introduction .......................................................................................................149
11.1.1 Brief EMI Theory ..............................................................................149
11.1.2 EMI Regulations and Certifications..................................................150
11.2 EMI Design Considerations...............................................................................150
11.2.1 Spread Spectrum Clocking (SSC)....................................................150

Design Guide 7
11.2.2 Differential Clocking .........................................................................151
11.2.3 PCI Bus Clock Control......................................................................152
11.2.4 Heatsink Effects ...............................................................................153
11.2.5 EMI Ground Frames and Faraday Cages ........................................153
11.2.6 EMI Test Capabilities .......................................................................154
11.3 Retention Mechanism Placement and Keep-Outs ............................................155
11.3.1 Grounding Techniques.....................................................................157
12 Platform Power Delivery Guidelines..............................................................159
12.1 Customer Reference Board Power Delivery .....................................................159
12.1.1 Processor Core Voltage ...................................................................161
12.1.2 2.5 V.................................................................................................161
12.1.3 1.25 V...............................................................................................161
12.1.4 1.8 V.................................................................................................161
12.1.5 1.2 V.................................................................................................161
12.1.6 5 VSB ...............................................................................................161
12.1.7 3.3 VSB ............................................................................................162
12.1.8 1.8 VSB ............................................................................................162
12.1.9 Power Summary...............................................................................162
12.2 Processor Power Distribution Guidelines..........................................................162
12.2.1 Processor Power Requirements.......................................................162
12.2.1.1 Multiple Voltages ................................................................162
12.2.1.2 Voltage Tolerance...............................................................163
12.2.2 Processor Current Requirements.....................................................163
12.2.3 Power Delivery Layout Requirements..............................................163
12.2.4 Voltage Regulator Requirements .....................................................164
12.2.4.1 Input Voltages and Currents...............................................165
12.2.4.2 Power Good Output (PWRGD)...........................................165
12.2.4.3 Fault Protection...................................................................166
12.2.5 VR Module 9.1 Recommendations...................................................166
12.2.6 VR Down Recommendations ...........................................................167
12.2.7 Voltage Sequencing .........................................................................169
12.2.8 VCCA, VCCIOPLL, and VSSA Filter Specifications.........................171
12.2.9 Processor Decoupling ......................................................................173
12.2.9.1 High-Frequency Decoupling ...............................................173
12.2.9.2 Bulk Decoupling..................................................................175
12.2.10 GTLREF[3:0] ....................................................................................175
12.2.11 Component Models ..........................................................................177
12.2.12 Measuring Transients.......................................................................177
12.3 MCH Power Delivery Guidelines.......................................................................177
12.3.1 DDR_VTT (1.25 V) Decoupling........................................................177
12.3.2 VCC_CPU (1.45 V Power Plane).....................................................177
12.3.3 DDR (2.5 V Power Plane) ................................................................178
12.3.4 Hub Interface (1.2 V Power Plane)...................................................178
12.3.5 Filter Specifications (1.2V Power Plane)..........................................179
12.3.6 MCH Power Sequencing Requirement ............................................180
12.4 Intel®ICH3-S Power Delivery Guidelines .........................................................181
12.4.1 1.8 V/3.3 V Power Sequencing ........................................................181
12.4.2 3.3V/V5REF Sequencing .................................................................182
12.4.3 Intel®ICH3-S Power Rails................................................................183
12.4.4 Intel®ICH3-S Decoupling Recommendations..................................183

8Design Guide
12.5 Intel® P64H2 Power Requirements ..................................................................185
12.5.1 Intel® P64H2 Current Requirements ...............................................185
12.5.2 Intel® P64H2 Decoupling Requirements .........................................185
12.5.3 PCIRST# Implementation.................................................................186
12.5.4 P64H2 Power Sequencing Requirement..........................................186
13 Schematic Checklist.............................................................................................187
13.1 Processor Schematic Checklist.........................................................................187
13.2 MCH Schematic Checklist.................................................................................193
13.3 Intel®ICH3-S Schematic Checklist...................................................................196
13.4 Intel®82870P2 P64H2 Schematic Checklist.....................................................204
13.5 CK408 Schematic Checklist..............................................................................209
14 Layout Checklist.....................................................................................................211
14.1 Processor Checklist ..........................................................................................211
14.2 Intel® E7500 MCH Layout Checklist.................................................................213
14.3 Intel® ICH3-S Layout Checklist.........................................................................216
15 Schematics...............................................................................................................221

Design Guide 9
Figures
1-1 Example Intel® Xeon™ Processor with 512 KB L2 Cache / Intel® E7500 Chipset
Based System Configuration23
2-1 Intel® Xeon™ Processor with 512 KB L2 Cache Quadrant Layout (Top View)..26
2-2 Intel®E7500 MCH Quadrant Layout (Top View).................................................27
2-3 Intel®ICH3-S Quadrant Layout (Top View) ........................................................28
2-4 Intel® P64H2 Quadrant Layout (Top View) .........................................................29
3-1 Intel® E7500 Chipset Customer Reference Board System Placement Example32
3-2 8 Layer, 50 ΩBoard with 5 mil Traces................................................................33
4-1 Intel® E7500 Chipset-Based System Clocking Diagram.....................................37
4-2 Source Shunt Termination...................................................................................38
4-3 Clock Skew As Measured from Agent to Agent ..................................................40
4-4 Trace Spacing for HOST_CLK Clocks................................................................40
4-5 Stuffing Options for CK408 and CK408B............................................................41
4-6 Topology for CLK66 ............................................................................................42
4-7 Clock Skew Requirements ..................................................................................43
4-8 Example of Adding a Single Connector...............................................................44
4-9 Example of Adding Two Connectors and/or a Riser ...........................................44
4-10 Topology for CLK33_ICH3-S...............................................................................45
4-11 Topology for CLK33 to PCI Device Down ...........................................................46
4-12 Topology for CLK33 to PCI Slot..........................................................................47
4-13 Topology for CLK14 ............................................................................................48
4-14 Topology for USB_CLK.......................................................................................49
4-15 Decoupling Capacitors Placement and Connectivity ..........................................50
5-1 Dual Processor System Bus Topology................................................................54
5-2 Trace Length Matching for the Dual Processor System Bus...............................57
5-3 RESET# Topology...............................................................................................59
5-4 Topology for Asynchronous GTL+ Signals Driven by the Processor ..................60
5-5 Recommended THERMTRIP# Circuit.................................................................61
5-6 Topology for Asynchronous GTL+ Signals Driven by the Chipset ......................61
5-7 Topology for PWRGOOD (CPUPWRGOOD)......................................................62
5-8 INIT# Routing Topology ......................................................................................62
5-9 Voltage Translator Circuit....................................................................................63
5-10 BR[3:0]# Connection for DP Configuration..........................................................64
6-1 4 DIMM per Channel Implementation..................................................................68
6-2 3 DIMM per Channel Implementation..................................................................68
6-3 Trace Width and Spacing for All DDR Signals Except CMDCLK/CMDCLK#......69
6-4 Source Synchronous Topology...........................................................................71
6-5 Trace Length Matching Requirements for Source Synchronous Routing ...........72
6-6 DQS To CMDCLK Pair Length Matching............................................................72
6-7 Command Clock Topology..................................................................................73
6-8 Trace Width/Spacing for CMDCLK/CMDCLK# Routing......................................74
6-9 Length Matching Requirements for Source Clocked Signal, CKE, and CS[7:0]#74
6-10 Source Clocked Signal Topology........................................................................75
6-11 Chip Select Topology..........................................................................................76
6-12 CKE Topology .....................................................................................................77
6-13 Receive Enable Signal Routing Guidelines.........................................................78
6-14 DDRCOMP Resistive Compensation..................................................................79
6-15 DDRCVOL and DDRCVOH Resistive Compensation.........................................79

10 Design Guide
6-16 DDR VREF Voltage Regulator............................................................................80
6-17 DDR VREF Voltage Divider ................................................................................80
6-18 DDR VTerm Plane ..............................................................................................81
6-19 DIMM Decoupling................................................................................................82
7-1 Signal Naming Convention on Both Sides of the Hub Interfaces........................83
7-2 Hub Interface 2.0 Length matching.....................................................................86
7-3 Hub Interface 2.0 Routing Guidelines for Device Down Solutions......................86
7-4 Hub Interface 2.0 Routing Guidelines for Hub Interface Connector Solutions....87
7-5 Hub Interface 2.0 with Locally Generated Voltage Divider Circuit ......................88
7-6 Hub Interface 2.0 RCOMP Circuits.....................................................................88
7-7 8-Bit Hub Interface 1.5 Routing...........................................................................89
7-8 Hub Interface 1.5 Locally Generated Reference Divider Circuits........................91
7-9 Hub Interface 1.5 RCOMP Circuits.....................................................................91
8-1 Typical PCI/PCI-X Routing..................................................................................94
8-2 Typical Hot Plug Routing.....................................................................................95
8-3 Hot Plug Clock Configuration..............................................................................96
8-4 No Hot Plug Clock Configuration ........................................................................96
8-5 Loop Clock Configuration....................................................................................97
8-6 IDSEL Sample Implementation Circuit................................................................98
8-7 Manually-Operated Retention Latch Sensor.....................................................101
8-8 Attention Button Implementation.......................................................................102
8-9 Tri-State Buffer Circuit Example........................................................................104
8-10 MUX Circuit Example........................................................................................105
8-11 Single Slot Parallel SMBus Circuit ....................................................................106
8-12 Reference Schematic for Single-Slot Parallel Mode .........................................107
8-13 Dual Slot Parallel SMBus Circuit.......................................................................110
8-14 Reference Schematic for Dual-Slot Parallel Mode............................................111
8-15 Four Slot Stutter Logic Implementation Example..............................................113
8-16 Reference Schematic for Serial Mode ..............................................................114
8-17 M66EN Isolation Switch Solution......................................................................116
8-18 M66EN Diode Solution......................................................................................117
9-1 Combination Host-Side/Device-Side IDE Cable Detection ...............................120
9-2 Connection Requirements for Primary IDE Connector .....................................121
9-3 Connection Requirements for Secondary IDE Connector.................................122
9-4 Example Speaker Circuit...................................................................................123
9-5 PCI Bus Layout Example..................................................................................124
9-6 Suggested USB Downstream Power Connection.............................................126
9-7 Intel® ICH3-S SMBus / SMLink Interface .........................................................127
9-8 Unified VCC_3.3 Architecture ...........................................................................128
9-9 RTCX1 and SUSCLK Relationship...................................................................128
9-10 RTC External Circuitry ......................................................................................129
9-11 RTC Connection When Not Using Internal RTC...............................................129
9-12 A Diode Circuit to Connect RTC External Battery.............................................131
9-13 RTCRST# External Circuit ................................................................................132
9-14 Platform LAN Connect .....................................................................................134
9-15 Point-to-Point Interconnect Guideline ...............................................................135
9-16 LAN_CLK Routing Example..............................................................................136
9-17 Routing a 90 Degree Bend................................................................................137
9-18 Ground Plane Separation..................................................................................139
9-19 Intel®82562ET/EM Termination .......................................................................143

Design Guide 11
9-20 Critical Dimensions for Component Placement.................................................143
9-21 Termination Plane.............................................................................................145
11-1 Spread Spectrum Modulation Profile.................................................................151
11-2 Impact of Spread Spectrum Clocking on Radiated Emissions..........................151
11-3 Cancellation of H-fields Through Inverse Currents ...........................................152
11-4 Conceptual Processor Ground Frame...............................................................154
11-5 Retention Mechanism Outline and Ground Pad Detail......................................155
11-6 Retention Mechanism Placement and Keep-Out Overview..............................156
11-7 EMI Ground Size and Location .........................................................................157
11-8 Retention Mechanism Ground Ring..................................................................158
12-1 Power Delivery Example...................................................................................160
12-2 Power Distribution Block Diagrams for Two-Way System Motherboard...........165
12-3 VRM VID Routing..............................................................................................167
12-4 Simplified VRD Circuit Example........................................................................167
12-5 Example Load Line Selection Circuit.................................................................168
12-6 VID Routing.......................................................................................................169
12-7 Power-Up and Power-Down Timing..................................................................170
12-8 Processor Filter Topology .................................................................................171
12-9 Filter Implementation 1: Using Discrete Resistor ..............................................172
12-10 Filter Implementation 2: No Discrete Resistor...................................................172
12-11 Decoupling Example for a Microstrip Baseboard Design..................................174
12-12 1206 Capacitor Pad and Via Layouts................................................................174
12-13 GTLREF Divider................................................................................................175
12-14 Suggested GTLREF Generation.......................................................................176
12-15 MCH Decoupling (Backside View) ....................................................................178
12-16 Filter Topology for VCCA_1.2 (DDR Interface).................................................179
12-17 Filter Topology for VCCAHI_1.2 (HUB Interface)..............................................179
12-18 Filter Topology for VCCAHI_1.2 (System Bus).................................................180
12-19 Power Sequencing Requirement for MCH ........................................................180
12-20 Sample 2.5 V Output Enable Control Logic.......................................................181
12-21 Example 1.8 V/3.3 V Power Sequencing Circuit...............................................182
12-22 Example 3.3 V/V5REF Sequencing Circuitry ....................................................183
12-23 3.3V PCI/PCI-X (VCC_3.3) Capacitor Placement.............................................186

12 Design Guide
Tables
1-1 Reference Documents ........................................................................................15
1-2 Intel® Xeon™ Processor with 512 KB L2 Cache Feature Set Overview............20
1-3 Platform Maximum Bandwidth Summary............................................................23
3-1 Assumptions for System Placement Example ....................................................31
3-2 E7500 Chipset Customer Reference Board Requirements ................................33
4-1 CK408B Clock Groups........................................................................................35
4-2 Platform System Clock-Reference......................................................................36
4-3 HOST_CLK[1:0]# Routing Guidelines.................................................................39
4-4 CLK66 Routing Guidelines..................................................................................42
4-5 CLK33_ICH3-S Routing Guidelines....................................................................45
4-6 CLK33 Routing Guidelines for PCI Device Down ...............................................46
4-7 CLK33 Routing Guidelines for PCI Slot ..............................................................47
4-8 CLK14 Routing Guidelines..................................................................................48
4-9 USBCLK Routing Guidelines ..............................................................................49
5-1 System Bus Signal Groups .................................................................................53
5-2 System Bus Routing Summary ...........................................................................55
5-3 2X and 4X Signal Groups....................................................................................56
5-4 Source Synchronous Signals with the Associated Strobes.................................56
5-5 AGTL+ Common Clock I/O Signals.....................................................................58
5-6 Asynchronous GTL+ and Miscellaneous Signals................................................59
5-7 BR[3:0]# Connection...........................................................................................64
6-1 DDR Channel Signal Groups ..............................................................................67
6-2 DQ/CB to DQS Mapping .....................................................................................70
6-3 Source Synchronous Signal Group Routing Guidelines .....................................71
6-4 Command Clock Pair Routing Guidelines...........................................................73
6-5 Source Clocked Signal Group Routing Guidelines .............................................75
6-6 Chip Select Routing Guidelines ..........................................................................76
6-7 Clock Enable Routing Guidelines........................................................................77
7-1 Hub Interface 2.0 Signal/Strobe Association.......................................................84
7-2 Hub Interface 2.0 Signal Groups.........................................................................84
7-3 Hub Interface 2.0 Routing Parameters................................................................84
7-4 Hub Interface 2.0 Reference Circuit Specifications.............................................87
7-5 Hub Interface 2.0 RCOMP Resistor Values........................................................88
7-6 Hub Interface 1.5 Signal Groups.........................................................................90
7-7 Hub Interface 1.5 Routing Parameters................................................................90
7-8 Hub Interface 1.5 Reference Circuit Specifications.............................................90
7-9 Hub Interface 1.5 RCOMP Resistor Values........................................................91
8-1 PCI/PCI-X Frequencies.......................................................................................93
8-2 Intel® P64H2 PCI/PCI-X Configuration Length Requirements ...........................94
8-3 Intel® P64H2 Hot Plug Configuration Length Requirements..............................95
8-4 Hot Plug Clock Routing Length Parameters .......................................................96
8-5 No Hot Plug Clock Routing Length Parameters..................................................96
8-6 Loop Clock Configuration Routing Length Parameters.......................................97
8-7 SMBus Address Configuration............................................................................98
8-8 Hot Plug Mode ..................................................................................................103
8-9 Frequency Matrix ..............................................................................................104
8-10 Single Slot Parallel Mode Hot Plug Signal Table ..............................................105
8-11 Hot Plug Controller Output Signal Reset Values...............................................106

Design Guide 13
8-12 Dual Slot Parallel Mode Hot Plug Signals Table ...............................................109
8-13 Shift Register Input Data ...................................................................................113
9-1 LAN Design Guide Section Reference..............................................................134
12-1 Power Summary................................................................................................162
12-2 Processor Current Step Parameters.................................................................163
12-3 Component Recommendation—Inductor..........................................................171
12-4 Component Recommendation—Capacitor........................................................171
12-5 Processor High-Frequency Capacitance Recommendations............................173
12-6 Processor Bulk Capacitance Recommendations ..............................................175
12-7 Various Component Models Used at Intel (Not Vendor Specifications)............177
12-8 ICH3-S Power Rail Terminology .......................................................................183
12-9 Intel®ICH3-S Decoupling Recommendations...................................................184
12-10 Intel® P64H2 Max Sustained Currents .............................................................185
12-11 Decoupling Capacitor Recommendations.........................................................185
13-1 Processor Schematic Checklist.........................................................................187
13-2 MCH Schematic Checklist.................................................................................193
13-3 Intel®ICH3-S Schematic Checklist ...................................................................196
13-4 Intel®P64H2 Schematic Checklist....................................................................204
13-5 CK408 Schematic Checklist..............................................................................209
14-1 Processor Layout Checklist...............................................................................211
14-2 MCH Layout Checklist.......................................................................................213
14-3 Intel® ICH3-S Layout Checklist.........................................................................216

14 Design Guide
Revision History
Revision Description Date
-001 Initial Release. February 2002
-002
Changed: Section 6.3; DDR Command Clock Figure Notes
Added: Section 12.5.4; New P64H2 Power Sequencing
Requirement
Updated Schematics to reflect changes identified above.
March 2002

Design Guide 15
Introduction
Introduction 1
The Intel®Xeon™ Processor with 512 KB L2 Cache and Intel®E7500 Chipset Platform Design
Guide documents Intel’s design recommendations for systems based on the Intel®Xeon™
Processor with 512 KB L2 Cache and the E7500 chipset. In addition to providing motherboard
design recommendations such as layout and routing guidelines, this document addresses system
design issues such as power delivery.
Carefully follow the design information, board schematics, debug recommendations, and system
checklists provided in this document. These design guidelines have been developed to ensure
maximum flexibility for board designers while reducing the risk of board related issues.
Note that the guidelines recommended in this document are based on experience and simulation
work done at Intel while developing Intel Xeon processor with 512 KB L2 cache / E7500 chipset-
based systems. This work is ongoing, and the recommendations are subject to change.
Board designers may use the associated Intel schematics as a reference. While the schematics cover
a specific design implementation, the core schematics remain the same for most E7500 chipset-
based platforms. The schematic set provides a reference schematic for each E7500 chipset
component as well as common motherboard options. Additional flexibility is possible through
other permutations of these options and components.
1.1 Reference Documentation
Note: For the latest revision and documentation number, contact your appropriate field representative.
Table 1-1. Reference Documents
Document Document
Number/Source
603-Pin Socket Design Guidelines http://developer.intel.com/design/
Xeon/guides/249672.htm
82562ET 10/100 Mbps Platform LAN Connect (PLC) Product Datasheet
APIC External Design Specification
AT Attachment - 6 with packet Interface (ATA/ATAPI - 6)
CK-408B Clock Synthesizer/Driver Specification Revision 1.1
ITP700 Debug Port Design Guide http://developer.intel.com/design/
Xeon/guides/
Intel®Xeon™ Processor with 512 KB L2 Cache Signal Integrity Models http://developer.intel.com/design/
Xeon/devtools
Intel®82801CA I/O Controller Hub 3 (ICH3-S) Datasheet 290733
Intel®PCI-64 Hub 2 (P64H2) Thermal and Mechanical Design Guidelines 298648
Intel®E7500 Chipset Thermal and Mechanical Design Guidelines 298647
Intel®PCI-64 Hub 2 (P64H2) Datasheet 290732
Intel®E7500 Chipset Memory Controller Hub (MCH) Datasheet 290730

Introduction
16 Design Guide
PCI Bus Power Management Interface Specification, Revision 1.1
http://www.pcisig.com/
specifications/
pci_bus_power_management_int
erface
PCI Hot Plug Specification, Revision 1.1 http://www.pcisig.com/
specifications/pci_hot_plug
PCI Local Bus Specification, Revision 2.2 http://www.pcisig.com/
specifications/conventional_pci
PCI-PCI Bridge Architecture Specification, Revision 1.1 http://www.pcisig.com/ specifications/
pci_to_pci_bridge_architecture
PCI Standard Hot-Plug Controller and Subsystem Specification, Revision 1.0 http://www.pcisig.com/
specifications/pci_hot_plug
PCI-X Specification, Revision 1.0a http://www.pcisig.com/
specifications/pci_x
System Management Bus Specification (SMBus), Revision 1.1 http://www.smbus.org/specs/
Universal Serial Bus Specification, Revision 1.1 http://www.usb.org/developers/
docs.html
VRM 9.1 DC-DC Converter Design Guidelines http://developer.intel.com/design/
Xeon/guides/
Intel®Xeon™ Processor Voltage Regulator Down (VRD) Design Guidelines http://developer.intel.com/design/
Xeon/guides/
Intel®Xeon™ Processor with 512 KB L2 Cache System Compatibility
Guidelines http://developer.intel.com/design/
Xeon/guides/
Intel®Xeon™ Processor Thermal Design Guidelines http://developer.intel.com/design/
Xeon/guides/298348.htm
Intel®Xeon™ Processor Thermal Solution Functional Specifications http://developer.intel.com/design/
Xeon/applnots/249673.htm
Intel®Xeon™ Processor with 512 KB L2 Cache Thermal Models http://developer.intel.com/design/
Xeon/devtools/
Intel®Xeon™ Processor with 512 KB L2 Cache Mechanical Model in IGES
Format http://developer.intel.com/design/
Xeon/devtools/
Intel®Xeon™ Processor with 512 KB L2 Cache Mechanical Model in ProE*
Format http://developer.intel.com/design/
Xeon/devtools/
Intel®Xeon™ Processor with 512 KB L2 Cache at 1.80 GHz, 2 GHz, and
2.20 GHz Datasheet http://developer.intel.com/design/
Xeon/datashts/298642.htm
AP-728 Intel®ICH Family Real Time Clock (RTC) Accuracy and
Considerations Under Test Conditions http://developer.intel.com/design/
chipsets/applnots/292276.htm
Table 1-1. Reference Documents
Document Document
Number/Source

Design Guide 17
Introduction
1.2 Conventions and Terminology
This section defines conventions and terminology used throughout the design guide.
Convention/Terminology Description
Aggressor A network that transmits a coupled signal to another network.
AGTL+ The Xeon™ processor family system bus uses a bus technology called AGTL+,
or Assisted Gunning Transceiver Logic. AGTL+ buffers are open-drain, and
require pull-up resistors to provide the high logic level and termination. AGTL+
output buffers differ from GTL+ buffers with the addition of an active pMOS pull-
up transistor to assist the pull-up resistors during the first clock of a low-to-high
voltage transition.
Asynchronous GTL+ Xeon processors do not utilize CMOS voltage levels on any signals that connect
to the processor. As a result, legacy input signals such as A20M#, IGNNE#,
INIT#, LINT0/INTR, LINT1/NMI, PWRGOOD, SMI#, SLP#, and STPCLK# utilize
GTL+ input buffers. Legacy output signals (FERR# and IERR#) and non-AGTL+
signals (THERMTRIP# and PROCHOT#) also utilize GTL+ output buffers. All of
these signals follow the same DC requirements as AGTL+ signals, however the
outputs are not actively driven high (during a logical 0 to 1 transition) by the
processor (the major difference between GTL+ and AGTL+). These signals do
not have setup or hold time specifications in relation to BCLK[1:0], and are
therefore referred to as “Asynchronous GTL+ Signals”. However, all of the
Asynchronous GTL+ signals are required to be asserted for at least two BCLKs
in order for the processor to recognize them.
Bus Agent A component or group of components that, when combined, represent a single
load on the AGTL+ bus.
Core Power Core power refers to a power rail that is on only during full-power operation.
These power rails are on when the active-low PSON signal is asserted to the
power supply. The core power rails that are distributed directly from the power
supply are: +12 V, +5 V, and +3.3 V.
Crosstalk The reception on a victim network of a signal imposed by aggressor network(s)
through inductive and capacitive coupling between the networks.
• Backward Crosstalk – Coupling that creates a signal in a victim network that
travels in the opposite direction as the aggressor’s signal.
• Forward Crosstalk – Coupling that creates a signal in a victim network that
travels in the same direction as the aggressor’s signal.
• Even Mode Crosstalk – Coupling from a signal or multiple aggressors when
all the aggressors switch in the same direction that the victim is switching.
• Odd Mode Crosstalk – Coupling from a signal or multiple aggressors when
all the aggressors switch in the opposite direction that the victim is switching.
Derived power A derived power rail is any power rail that is generated from another power rail
using an on-board voltage regulator. For example, +2.5 V is derived from a +5 V
power rail using a voltage regulator.
Dual Processor (DP) Used to specify a system configuration using two processors.
Electromagnetic
Compatibility (EMC) The successful operation of electronic equipment in its intended electromagnetic environment.
Electromagnetic
Interference (EMI) Electromagnetic radiation from an electrical source that interrupts the normal function of an electronic device.

Introduction
18 Design Guide
Flight Time Flight time is a term in the timing equation that includes the signal propagation
delay, any effects the system has on the Tco of the driver, plus any adjustments
to the signal at the receiver needed to guarantee the setup time of the receiver.
More precisely, flight time is defined as:
• The time difference between a signal at the input pin of a receiving agent
crossing the switching voltage (adjusted to meet the receiver manufacturer’s
conditions required for AC timing specifications; i.e., ringback, etc.) and the
output pin of the driving agent crossing the switching voltage when the driver
is driving a test load used to specify the driver’s AC timings.
• Maximum and Minimum Flight Time – Flight time variations are caused by
many different parameters. The more obvious causes include variation of
the board dielectric constant, changes in load condition, crosstalk, power
noise, variation in termination resistance, and differences in I/O buffer
performance as a function of temperature, voltage, and manufacturing
process. Some less obvious causes include effects of Simultaneous
Switching Output (SSO) and packaging effects.
• Maximum flight time is the largest acceptable flight time that a network
experiences under all conditions.
• Minimum flight time is the smallest acceptable flight time that a network
experiences under all conditions.
Full-power During full-power operation, all components on the motherboard remain
powered. Note that full-power operation includes both the full-on operating state,
and the S1 (processor stop-grant) state.
GTLREF Reference voltage for AGTL+ input pins.
Inter-Symbol
Interference (ISI) The effect of a previous signal (or transition) on the interconnect delay. For example, when a signal is transmitted down a line, and the reflections due to the
transition have not completely dissipated, the following data transition launched
onto the bus is affected. ISI is dependent upon frequency, time delay of the line,
and the reflection coefficient at the driver and receiver.ISI can impact both timing
and signal integrity.
Network The network is the trace of a Printed Circuit Board (PCB) that completes an
electrical connection between two or more components.
Overshoot The maximum voltage observed for a signal at the device pad, measured with
respect to VCC.
Pad The electrical contact point of a semiconductor die to the package substrate. A
pad is only observable in simulations.
Pin The contact point of a component package to the traces on a substrate, such as
the motherboard. Signal quality and timings can be measured at the pin.
Power-Good “Power-Good,” “PWRGOOD,” or “CPUPWRGOOD” (an active high signal)
indicates that all of the system power supplies and clocks are stable.
PWRGOOD should go active a predetermined time after system voltages are
stable and should go inactive as soon as any of these voltages fail their
specifications.
Power Rails A power supply has five power rails: +12 V, –12 V, +5 V, +3.3 V, and +5 VSB. In
addition to these power rails from the power supply, several other power rails are
created by voltage regulators on the Reference Board.
Ringback The voltage to which a signal changes after reaching its maximum absolute
value. Ringback may be caused by reflections, driver oscillations, or other
transmission line phenomena.
System Bus The System Bus is the bus which connects the processor to the platform.
Setup Window The time between the beginning of Setup to Clock (TSU_MIN) and the arrival of
a valid clock edge. This window may be different for each type of bus agent in
the system.
Convention/Terminology Description

Design Guide 19
Introduction
1.3 System Overview
The E7500 chipset is Intel’s first generation server chipset designed for use with the Xeon
processor. The architecture of the chipset provides the performance and feature-set required for
dual-processor based severs in the entry-level and mid-range, front-end and general-purpose server
market segments. A new chipset component interconnect, the Hub Interface 2.0 (HI2.0), is
designed into the E7500 chipset to provide more efficient communication between chipset
components for high-speed I/O. Each HI2.0 provides 1.066 GB/s I/O bandwidth. The E7500 MCH
has three HI2.0 connections, delivering 3.2 GB/s bandwidth for high-speed I/O, which can be used
for PCI/PCI-X bridges. The system bus, used to connect the processor with the E7500 chipset,
utilizes a 400 MHz transfer rate for data transfers, delivering 3.2 GB/s. The E7500 chipset
architecture supports a 144-bit wide, 200 MHz DDR memory interface also capable of transferring
data at 3.2 GB/s.
In addition to these performance features, E7500 chipset-based platforms also provide the RASUM
(Reliability, Availability, Serviceability, Usability, and Manageability) features required for entry-
level and mid-range servers. These features include: Chipkill* technology ECC for memory, ECC
for all high-performance I/O, out-of-band manageability through SMBus target interfaces on all
major components, memory scrubbing and auto-initialization, processor thermal monitoring, and
hot-plug PCI. For a complete list of the features on this platform, refer to the component datasheets
listed in Section 1.1.
Simultaneous Switching
Output (SSO) Effects which are differences in electrical timing parameters and degradation in signal quality caused by multiple signal outputs simultaneously switching voltage
levels in the opposite direction from a single signal or in the same direction.
These are called odd mode and even mode switching, respectively. This
simultaneous switching of multiple outputs creates higher current swings that
may cause additional propagation delay (“push-out”) or a decrease in
propagation delay (“pull-in”). These SSO effects may impact the setup and/or
hold times and are not always taken into account by simulations. System timing
budgets should include margin for SSO effects.
Standby Power Rail Standby power is supplied by the power supply during times when the system is
powered down. The purpose is to maintain functions that always need to be
enabled, such as the date and time-of-day within the BIOS. The power supply
provides a +5 VSB power rail.
Stub The branch from the bus trunk terminating at the pad of an agent.
Trunk The main connection, excluding interconnect branches, from one end agent pad
to the other end agent pad.
Undershoot The minimum voltage extending below VSS observed for a signal at the device
pad.
VCC_CPU VCC_CPU is the core power for the processor. The system bus is terminated to
VCC_CPU.
Victim A network that receives a coupled crosstalk signal from another network is called
the victim network.
VRM 9.1 “VRM 9.1” refers to the Voltage Regulator Module specification for the Xeon
processor. It is a DC-DC converter module that supplies the required voltage and
current to a single processor.
Convention/Terminology Description

Introduction
20 Design Guide
1.3.1 Intel®Xeon™ Processor with 512 KB L2 Cache
The Intel Xeon processor with 512 KB L2 cache is the second generation of microprocessors
targeted for severs and workstations using the Intel®NetBurst™ microarchitecture. The Xeon
processor delivers performance levels that are significantly higher than previous generations of IA-
32 processors. The E7500 chipset supports all speeds of the Intel Xeon processor with 512 KB L2
cache.
Unless otherwise noted, the term “processor” refers to the Xeon processor.
The Xeon processor includes the following advanced microarchitecture features:
•Hyper Pipelined Technology.
•Advanced Dynamic Execution.
•Execution Trace Cache.
•Streaming SIMD (single instruction, multiple data) Extensions 2.
•Advanced Transfer Cache.
•Enhanced Floating Point and Multimedia Engine.
The Intel Xeon processor system bus utilizes a split-transaction, deferred reply protocol similar to
that of the Intel®Pentium III Xeon™ processor bus, however the system bus is not compatible
with the Pentium III Xeon processor bus. The system bus uses source-synchronous transfer of
address and data to improve performance and enables addressing at 2X the system bus frequency
of 100 MHz and data transfers at 4X the system bus frequency of 100 MHz. This allows the
processors to transfer data at 3.2 GB/s.
The Xeon processor provides manageability features consistent with Intel®Pentium®III Xeon™
processors. These features include the Processor Information ROM, the OEM EEPROM, and the
processor thermal sensor; all of which are accessed through the System Management Bus
(SMBus). The Processor Information ROM is a 128-byte read-only device that incorporates Intel
processor specific data. The OEM EEPROM, also known as the “scratchpad EEPROM,” is a
128-byte read/write EEPROM in which an OEM may program system specific data. The thermal
sensor monitors the temperature of the processor die.
Table 1-2. Intel®Xeon™ Processor with 512 KB L2 Cache Feature Set Overview
Feature Xeon™
L2 Cache 512 KB
Data Bus Transfer Rate 3.2 GB/s
Multi-Processor Support 1–2 CPUs
Manageability Features Intel and OEM EEPROMs and
thermal sensor on package
Package 603-pin micro-PGA
Operating Voltage 1.50 V