PCI Express External Cabling Specification, Revision 1.0

142 Pages·2007·1.947 MB·English

PCI Express® External Cabling
Specification
Revision 1.0

January 4, 2007
PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
Revision Revision History DATE
1.0 Initial public release. 1/4/2007

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Copyright © 2007 PCI-SIG
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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
Contents
1. INTRODUCTION.................................................................................................................11
1.1. TERMS AND ACRONYMS................................................................................................11
1.2. REFERENCE DOCUMENTS...............................................................................................12
1.3. DOCUMENTATION CONVENTIONS..................................................................................12
1.4. SPECIFICATION CONTENTS.............................................................................................13
1.5. OBJECTIVES...................................................................................................................13
1.6. OVERVIEW.....................................................................................................................14
2. AUXILIARY SIGNALS.......................................................................................................15
2.1. SIGNAL COMPATIBILITY MATRIX..................................................................................16
2.2. POWER-DOMAIN ISOLATION..........................................................................................17
2.3. CABLE REFERENCE CLOCK (REQUIRED)........................................................................18
2.3.1. Clocking Dependencies...........................................................................................19
2.3.2. Spread Spectrum Clock (SSC) Sources...................................................................19
2.3.3. AC-coupling............................................................................................................19
2.3.4. Impact of Jitter on Bit Error Ratio (BER)..............................................................19
2.3.5. CREFCLK Distribution..........................................................................................20
2.4. CABLE PRESENT (REQUIRED).........................................................................................20
2.5. CABLE PLATFORM RESET (REQUIRED)..........................................................................22
2.6. CABLE POWER ON (REQUIRED).....................................................................................23
2.7. SIDEBAND RETURN (REQUIRED)....................................................................................24
2.8. CABLE WAKE# (REQUIRED).........................................................................................24
2.9. POWER (OPTIONAL +3.3V)............................................................................................26
2.10. ESD...............................................................................................................................26
2.11. POWER SEQUENCING.....................................................................................................26
2.11.1. Power-Up Sequencing.........................................................................................26
2.11.2. Power-Down Sequencing....................................................................................27
2.11.3. Power Management Sequencing.........................................................................29
2.12. AUXILIARY SIGNAL PARAMETRIC SPECIFICATIONS.......................................................30
2.12.1. DC Specifications................................................................................................30
2.12.2. AC Specifications for Single-Ended Signals.......................................................32
2.12.3. Cable Reference Clock Specification..................................................................33
2.12.4. Phase Jitter..........................................................................................................37
3. PCI EXPRESS SIGNALS.....................................................................................................39
3.1. INTERCONNECT..............................................................................................................39
3.1.1. Link Definition........................................................................................................40
3.2. ELECTRICAL BUDGETS...................................................................................................41
3.2.1. AC-coupling............................................................................................................41
3.2.2. Insertion Loss..........................................................................................................42
3.2.3. Jitter Budgets..........................................................................................................43
3.2.4. Interconnect Jitter Budget Allocation.....................................................................44
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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
3.2.5. Crosstalk.................................................................................................................46
3.2.6. Lane-to-Lane Skew..................................................................................................46
3.2.7. Equalization............................................................................................................46
3.2.8. Skew Within the Differential Pair (Intra-Pair Skew)..............................................46
3.3. EYE DIAGRAMS COMPLIANCE MEASUREMENTS............................................................47
3.3.1. Transmitter Compliance Eye..................................................................................47
3.3.2. Receiver Compliance Eye.......................................................................................48
3.4. ESD...............................................................................................................................49
3.5. LINK POWER MANAGEMENT..........................................................................................49
4. CABLE INTEROPERABILITY...........................................................................................51
4.1. CABLE CONNECTOR IDENTIFICATION............................................................................51
4.2. CABLE LENGTH..............................................................................................................51
4.3. CABLE ASSEMBLY CONFIGURATION..............................................................................52
5. CONNECTOR DEFINITION...............................................................................................53
5.1. SIGNAL DESCRIPTION....................................................................................................53
5.2. X1 CONNECTOR DEFINITION..........................................................................................53
5.2.1. Pin-out (x1).............................................................................................................53
5.2.2. Board-Side Mechanical Drawings..........................................................................55
5.2.3. Recommended Footprint.........................................................................................57
5.2.4. Electrical Requirements..........................................................................................60
5.2.5. Current and Voltage Rating Requirements.............................................................61
5.2.6. Mechanical Requirements.......................................................................................61
5.3. X4 CONNECTOR DEFINITION..........................................................................................62
5.3.1. Pin-out (x4).............................................................................................................62
5.3.2. Board-Side Mechanical Drawings..........................................................................64
5.3.3. Recommended Foot Print.......................................................................................71
5.3.4. Electrical Requirements..........................................................................................73
5.3.5. Current and Voltage Rating Requirements.............................................................73
5.3.6. Mechanical Requirements.......................................................................................74
5.4. X8 CONNECTOR DEFINITION..........................................................................................74
5.4.1. Pin-out (x8).............................................................................................................74
5.4.2. Board-Side Mechanical Drawings..........................................................................77
5.4.3. Recommended Footprint.........................................................................................86
5.4.4. Electrical Requirements..........................................................................................88
5.4.5. Current and Voltage Rating Requirements.............................................................88
5.4.6. Mechanical Requirements.......................................................................................89
5.5. X16 CONNECTOR DEFINITION........................................................................................89
5.5.1. Pin-out (x16)...........................................................................................................89
5.5.2. Board-Side Mechanical Drawings..........................................................................94
5.5.3. Recommended Footprint.......................................................................................100
5.5.4. Electrical Requirements........................................................................................102
5.5.5. Current and Voltage Rating Requirements...........................................................102
5.5.6. Mechanical Requirements.....................................................................................102
5.6. CONNECTOR DURABILITY............................................................................................103
5.7. ENVIRONMENTAL PERFORMANCE................................................................................103
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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
6. CABLE SPECIFICATION..................................................................................................105
6.1. CABLE CONFIGURATION..............................................................................................105
6.1.1. x1 Cable Assembly................................................................................................105
6.1.2. x4 Cable Assembly................................................................................................110
6.1.3. x8 Cable Assembly................................................................................................117
6.1.4. x16 Cable Assembly..............................................................................................125
6.2. REQUIREMENTS............................................................................................................134
6.2.1. Physical and Mechanical Performance................................................................134
6.2.2. Electrical Performance.........................................................................................135
6.3. SHIELDING...................................................................................................................139
6.4. ACTIVE CABLES...........................................................................................................139
ACKNOWLEDGEMENTS.........................................................................................................141

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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
Figures
FIGURE 2-1: CREFCLK IMPLEMENTATION DESCRIPTION............................................................18
FIGURE 2-2: TERMINATING UNUSED CREFCLK..........................................................................18
FIGURE 2-3: CREFCLK TIMING SKEW.........................................................................................20
FIGURE 2-4: CPRSNT# SIGNALING WITH POWER ISOLATION.......................................................21
FIGURE 2-5: CPERST# SIGNALING WITH POWER ISOLATION.......................................................22
FIGURE 2-6: CPERST# TO CREFCLK TIMING.............................................................................22
FIGURE 2-7: CPWRON SIGNALING WITH POWER ISOLATION.......................................................23
FIGURE 2-8: CPWRON TIMING....................................................................................................23
FIGURE 2-9: CWAKE# SIGNALING WITH POWER ISOLATION.......................................................25
FIGURE 2-10: POWER-UP SEQUENCING.........................................................................................27
FIGURE 2-11: POWER-DOWN SEQUENCING...................................................................................28
FIGURE 2-12: POWER MANAGEMENT SEQUENCING (S0 TO S3/S4 TO S0).....................................30
FIGURE 2-13: SINGLE-ENDED CREFCLK WAVEFORM.................................................................34
FIGURE 2-14: SINGLE-ENDED MEASUREMENT POINTS FOR DELTA CROSS POINT.........................35
FIGURE 2-15: SINGLE-ENDED MEASUREMENT POINTS FOR RISE AND FALL TIME MATCHING......35
FIGURE 2-16: DIFFERENTIAL MEASUREMENT FOR DUTY CYCLE AND PERIOD..............................35
FIGURE 2-17: DIFFERENTIAL MEASUREMENT POINTS FOR RISE AND FALL TIME..........................35
FIGURE 2-18: DIFFERENTIAL MEASUREMENT POINTS FOR RINGBACK..........................................36
FIGURE 2-19: CREFCLK MEASUREMENT AND TEST LOAD..........................................................36
FIGURE 3-1: ELECTRICAL PARAMETER ALLOCATION....................................................................40
FIGURE 3-2: LOSS AND JITTER DEFINITION POINTS.......................................................................41
FIGURE 3-3: JITTER BUDGET ALLOCATION...................................................................................45
FIGURE 3-4: TRANSMITTER COMPLIANCE EYE..............................................................................47
FIGURE 3-5: RECEIVER COMPLIANCE EYE....................................................................................48
FIGURE 5-1: X1 BOARD-SIDE CONNECTOR FORM FACTOR............................................................55
FIGURE 5-2: X1 BOARD-SIDE RECOMMENDED FOOTPRINT...........................................................57
FIGURE 5-3: X1 RECOMMENDED PANEL CUT OUT........................................................................58
FIGURE 5-4: X1 PLUG TERMINAL TIP GEOMETRY.........................................................................59
FIGURE 5-5: X1 RECEPTACLE TERMINAL TIP GEOMETRY.............................................................59
FIGURE 5-6: X1 MATED INTERFACE GEOMETRY...........................................................................59
FIGURE 5-7: ISOMETRIC VIEW OF X4 BOARD-SIDE CONNECTOR...................................................64
FIGURE 5-8: X4 BOARD-SIDE CONNECTOR FORM FACTOR............................................................64
FIGURE 5-9: X4 EMI GUIDE HOUSING ASSEMBLY........................................................................66
FIGURE 5-10: X4 STANDARD (0°) EMI GUIDE HOUSING ASSEMBLY SIDE VIEW...........................66
FIGURE 5-11: X4 PCI EXPANSION CARD (1°) EMI GUIDE HOUSING ASSEMBLY SIDE VIEW.........66
FIGURE 5-12: X4 EMI GUIDE HOUSING ASSEMBLY TOP VIEW.....................................................67
FIGURE 5-13: X4 EMI GUIDE HOUSING ASSEMBLY BOTTOM VIEW..............................................67
FIGURE 5-14: X4 (0º) EMI GUIDE HOUSING ASSEMBLY SECTION SIDE VIEW................................68
FIGURE 5-15: X4 (1º) EMI GUIDE HOUSING ASSEMBLY SECTION SIDE VIEW...............................68
FIGURE 5-16: X4 EMI GUIDE HOUSING ASSEMBLY FACE VIEW...................................................68
FIGURE 5-17: X4 EMI GUIDE HOUSING ASSEMBLY BRACKET WINDOW.......................................69
FIGURE 5-18: X4 CONNECTOR AND GUIDE HOUSING FOOTPRINT..................................................71
FIGURE 5-19: ISOMETRIC VIEW OF X8 BOARD-SIDE CONNECTOR.................................................77
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FIGURE 5-20: X8 BOARD-SIDE CONNECTOR FORM FACTOR..........................................................78
FIGURE 5-21: X8 EMI GUIDE HOUSING ASSEMBLY......................................................................79
FIGURE 5-22: X8 STANDARD (0°) EMI GUIDE HOUSING ASSEMBLY SIDE VIEW...........................80
FIGURE 5-23: X8 EXPANSION CARD (1°) EMI GUIDE HOUSING ASSEMBLY SIDE VIEW................80
FIGURE 5-24: X8 EMI GUIDE HOUSING ASSEMBLY TOP VIEW.....................................................81
FIGURE 5-25: X8 EMI GUIDE HOUSING ASSEMBLY BOTTOM VIEW..............................................82
FIGURE 5-26: X8 (0º) EMI GUIDE HOUSING ASSEMBLY SECTION SIDE VIEW...............................82
FIGURE 5-27: X8 (1º) EMI GUIDE HOUSING ASSEMBLY SECTION SIDE VIEW...............................82
FIGURE 5-28: X8 EMI GUIDE HOUSING ASSEMBLY FACE VIEW...................................................83
FIGURE 5-29: X8 EMI GUIDE HOUSING ASSEMBLY BRACKET WINDOW.......................................83
FIGURE 5-30: X8 CONNECTOR AND GUIDE HOUSING FOOTPRINT..................................................86
FIGURE 5-31: ISOMETRIC VIEW OF X16 CONNECTOR ASSEMBLY..................................................94
FIGURE 5-32: X16 BOARD-SIDE CONNECTOR FORM FACTOR........................................................95
FIGURE 5-33: X16 CONNECTOR ASSEMBLY BRACKET WINDOW...................................................98
FIGURE 5-34: X16 CONNECTOR ASSEMBLY SIDE VIEW.................................................................98
FIGURE 5-35: X16 CONNECTOR ASSEMBLY FOOTPRINT..............................................................100
FIGURE 6-1: X1 CABLE ASSEMBLY.............................................................................................105
FIGURE 6-2: X1 CABLE ASSEMBLY TOP VIEW.............................................................................105
FIGURE 6-3: X1 CABLE ASSEMBLY SIDE VIEW............................................................................106
FIGURE 6-4: X1 CABLE ASSEMBLY PIN-OUT...............................................................................106
FIGURE 6-5: X1 CABLE ASSEMBLY FORM FACTOR......................................................................107
FIGURE 6-6: X1 CABLE BEND RADIUS.........................................................................................108
FIGURE 6-7: X4 CABLE ASSEMBLY.............................................................................................110
FIGURE 6-8: X4 CABLE ASSEMBLY TOP AND BOTTOM VIEWS....................................................110
FIGURE 6-9: X4 CABLE ASSEMBLY SIDE VIEW............................................................................110
FIGURE 6-10: X4 CABLE ASSEMBLY END VIEW..........................................................................111
FIGURE 6-11: X4 CABLE ASSEMBLY LATCH FEATURE DETAIL...................................................111
FIGURE 6-12: X4 PIN LOCATIONS................................................................................................112
FIGURE 6-13: X4 CABLE SIDE CONNECTOR MODULE INTERFACE...............................................114
FIGURE 6-14: X4 CABLE BEND RADIUS.......................................................................................115
FIGURE 6-15: X8 CABLE ASSEMBLY...........................................................................................117
FIGURE 6-16: X8 CABLE ASSEMBLY TOP AND BOTTOM VIEWS..................................................117
FIGURE 6-17: X8 CABLE ASSEMBLY SIDE VIEW..........................................................................118
FIGURE 6-18: X8 CABLE ASSEMBLY END VIEW..........................................................................118
FIGURE 6-19: X8 CABLE ASSEMBLY LATCH FEATURE DETAIL...................................................119
FIGURE 6-20: X8 PIN LOCATIONS................................................................................................119
FIGURE 6-21: X8 CABLE BEND RADIUS.......................................................................................121
FIGURE 6-22: X8 CABLE SIDE CONNECTOR MODULE INTERFACE...............................................122
FIGURE 6-23: X16 CABLE ASSEMBLY.........................................................................................125
FIGURE 6-24: X16 CABLE ASSEMBLY TOP AND BOTTOM VIEWS................................................126
FIGURE 6-25: X16 CABLE ASSEMBLY SIDE VIEW........................................................................126
FIGURE 6-26: X16 CABLE ASSEMBLY END VIEW........................................................................126
FIGURE 6-27: X16 CABLE ASSEMBLY LATCH FEATURE DETAIL.................................................127
FIGURE 6-28: X16 PIN LOCATIONS..............................................................................................127
FIGURE 6-29: X16 CABLE BEND RADIUS.....................................................................................129
FIGURE 6-30: X16 CABLE SIDE CONNECTOR MODULE INTERFACE.............................................130
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FIGURE 6-31: CABLE ASSEMBLY INSERTION LOSS......................................................................136
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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
Tables
TABLE 2-1: SIGNAL COMPATIBILITY MATRIX 16
TABLE 2-2: DC SPECIFICATIONS 30
TABLE 2-3: AC SPECIFICATIONS FOR SINGLE-ENDED SIDEBAND SIGNALS 32
TABLE 2-4: REFERENCE CLOCK SOURCE AC TIMING 33
TABLE 3-1: 2.5 GT/S INSERTION LOSS BUDGET ALLOCATION 42
TABLE 3-2: TOTAL SYSTEM JITTER DISTRIBUTION 44
TABLE 3-3: INTERCONNECT JITTER BUDGET 45
TABLE 3-4: ALLOWABLE INTERCONNECT LANE-TO-LANE SKEW 46
TABLE 3-5: TRANSMITTER PATH COMPLIANCE EYE REQUIREMENTS 47
TABLE 3-6: RECEIVER PATH COMPLIANCE EYE REQUIREMENTS 48
TABLE 5-1: X1 CONNECTOR PIN ASSIGNMENT 53
TABLE 5-2: X1 BOARD-SIDE CONNECTOR FORM FACTOR DIMENSIONS 55
TABLE 5-3: X1 BOARD-SIDE RECOMMENDED FOOTPRINT DIMENSIONS 57
TABLE 5-4: X1 RECOMMENDED PANEL CUT OUT DIMENSIONS 58
TABLE 5-5: X1 INTERFACE GEOMETRY DIMENSIONS 60
TABLE 5-6: X1 CONNECTOR ELECTRICAL PERFORMANCE REQUIREMENTS 60
TABLE 5-7: X1 CURRENT AND VOLTAGE RATING REQUIREMENTS 61
TABLE 5-8: X1 CONNECTOR PHYSICAL AND MECHANICAL PERFORMANCE REQUIREMENTS 61
TABLE 5-9: X4 CONNECTOR PIN ASSIGNMENT 62
TABLE 5-10: X4 BOARD-SIDE CONNECTOR DIMENSIONS 65
TABLE 5-11: X4 EMI GUIDE HOUSING ASSEMBLY MECHANICAL DIMENSIONS 69
TABLE 5-12: X4 CONNECTOR AND GUIDE HOUSING FOOTPRINT DIMENSIONS 71
TABLE 5-13: X4 CONNECTOR ELECTRICAL PERFORMANCE REQUIREMENTS 73
TABLE 5-14: X4 CURRENT AND VOLTAGE RATING REQUIREMENTS 73
TABLE 5-15: X4 CONNECTOR PHYSICAL AND MECHANICAL PERFORMANCE REQUIREMENTS 74
TABLE 5-16: X8 CONNECTOR PIN ASSIGNMENT 74
TABLE 5-17: X8 BOARD-SIDE CONNECTOR DIMENSIONS 78
TABLE 5-18: X8 EMI GUIDE HOUSING ASSEMBLY MECHANICAL DIMENSIONS 84
TABLE 5-19: X8 CONNECTOR AND GUIDE HOUSING FOOTPRINT DIMENSIONS 87
TABLE 5-20: X8 CONNECTOR ELECTRICAL REQUIREMENTS 88
TABLE 5-21: X8 CURRENT AND VOLTAGE RATING REQUIREMENTS 88
TABLE 5-22: X8 CONNECTOR PHYSICAL AND MECHANICAL REQUIREMENTS 89
TABLE 5-23: X16 CONNECTOR PIN ASSIGNMENT 89
TABLE 5-24: X16 BOARD-SIDE CONNECTOR DIMENSIONS 96
TABLE 5-25: X16 CONNECTOR ASSEMBLY BRACKET WINDOW DIMENSIONS 99
TABLE 5-26: X16 CONNECTOR ASSEMBLY FOOTPRINT DIMENSIONS 101
TABLE 5-27: X16 CONNECTOR ELECTRICAL PERFORMANCE REQUIREMENTS 102
TABLE 5-28: X16 CURRENT AND VOLTAGE RATING REQUIREMENTS 102
TABLE 5-29: X16 CONNECTOR PHYSICAL AND MECHANICAL PERFORMANCE REQUIREMENTS 102
TABLE 5-30: CONNECTOR DURABILITY REQUIREMENTS 103
TABLE 6-1: X1 CABLE ASSEMBLY DIMENSIONS 106
TABLE 6-2: X1 CABLE ASSEMBLY DIMENSIONS 108
TABLE 6-3: X1 CABLE BEND RADIUS DIMENSIONS 109
TABLE 6-4: X1 CABLE SIDE WIRE CONNECTIONS 109
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PCI EXPRESS EXTERNAL CABLING SPECIFICATION, REV. 1.0
TABLE 6-5: X4 CABLE SIDE CONNECTOR DIMENSIONS 112
TABLE 6-6: X4 CABLE SIDE CONNECTOR MODULE INTERFACE DIMENSIONS 114
TABLE 6-7: X4 CABLE BEND RADIUS DIMENSIONS 115
TABLE 6-8: X4 CABLE WIRE CONNECTIONS 116
TABLE 6-9: X8 CABLE SIDE CONNECTOR DIMENSIONS 120
TABLE 6-10: X8 CABLE BEND RADIUS DIMENSIONS 122
TABLE 6-11: X8 CABLE SIDE CONNECTOR MODULE INTERFACE DIMENSIONS 123
TABLE 6-12: X8 CABLE WIRE CONNECTIONS 123
TABLE 6-13: X16 CABLE SIDE CONNECTOR DIMENSIONS 128
TABLE 6-14: X16 CABLE BEND RADIUS DIMENSIONS 129
TABLE 6-15: X16 CABLE SIDE CONNECTOR MODULE INTERFACE DIMENSIONS 130
TABLE 6-16: X16 CABLE WIRE CONNECTIONS 131
TABLE 6-17: CABLE FLEX REQUIREMENTS 134
TABLE 6-18: CABLE ASSEMBLY DIFFERENTIAL CHARACTERISTICS SUMMARY 135

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