Hardware Design Guidelines
February
Document No 305261 Revision
February
Contents
Introduction
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5.0 General Layout and Routing Guide
6.0 PCI Interface Design Considerations
Document Number 305261, Revision
Figures
Tables
Revision History
Date
Revision
Description
February
1.1Content Overview
1.0Introduction
1.2Related Documentation
1.3Acronyms and Abbreviations
1.4Overview
List of Acronyms and Abbreviations
32-bitPCI interface Master/Target 33/66 MHz
Figure 1. Intel IXP465 Component Block Diagram
MII/SMII
Cryptography
Unit
1.5Typical Applications
2.0System Architecture
2.1System Architecture Description
2.2System Memory Map
JTAG
IntelIXP46X Product
Line of Network
Processors
3.1Soft Fusible Features
Signal Type Definitions
3.0General Hardware Design Considerations
Table
3.2.1Signal Interface
Soft Fusible Features
3.2DDR-266SDRAM Interface
DDR SDRAM Interface Pin Description Sheet 1 of
DDR SDRAM Interface Pin Description Sheet 2 of
3.3Expansion Bus
3.2.2DDR SDRAM Memory Interface
3.2.3DDR SDRAM Initialization
3.3.1Signal Interface
3.3.2Reset Configuration Straps
Expansion Bus Signal Recommendations
Boot/Reset Strapping Configuration Sheet 1 of
Table
Name
Function
Boot/Reset Strapping Configuration Sheet 2 of
3.3.38-BitDevice Interface
3.3.416-BitDevice Interface
3.3.532-BitDevice Interface
Byte Access
16-Bit-WordAccess
32-Bit-WordAccess
8-BitDevice
Byte Access
16-Bit-WordAccess
32-Bit-WordAccess
8-BitDevice
Intel Flash
3.3.6Flash Interface
Figure 5. Flash Interface Example
16-Bit-WordAccess
3.4UART Interface
3.3.7SRAM Interface
3.3.8Design Notes
Figure 6. Expansion Bus SRAM Interface
3.4.1Signal Interface
UART Signal Recommendations
Connector
MII/SMII Interface
Figure 7. UART Interface Example
UART Interface
3.5.1Signal Interface MII
MII NPE A Signal Recommendations
MII NPE B Signal Recommendations Sheet 1 of
MII NPE B Signal Recommendations Sheet 2 of
MII NPE C Signal Recommendations
3.5.2Device Connection, MII
Figure 8. MII Interface Example
10/100
3.5.3Signal Interface, SMII
3.6GPIO Interface
3.5.4Device Connection, SMII
Figure 9. SMII Interface Example
3.6.1Signal Interface
GPIO Signal Recommendations
3.6.2Design Notes
3.7.1Signal Interface
I2C Signal Recommendations
3.7I2C Interface
3.7.2Device Connection
3.8USB Interface
Figure 10. I2C EEPROM Interface Example
Product Line
Network Processor
3.8.1Signal Interface
USB Host/Device Signal Recommendations
3.8.2Device Connection
Figure 11. USB Host Down Stream Interface Example
Host
Device
3.9UTOPIA Level 2 Interface
Figure 12. USB Device Interface Example
Device
Host
3.9.1Signal Interface
UTOPIA Signal Recommendations
3.9.2Device Connection
3.10HSS Interface
Figure 13. UTOPIA Interface Example
Analog Front
ATM Layer Device
3.10.1Signal Interface
High-Speed,Serial Interface
High-Speed,Serial Interface
Transmit frame
3.11SSP Interface
3.10.2Device Connection
Figure 14. HSS Interface Example
3.11.1Signal Interface
3.11.2Device Connection
Synchronous Serial Peripheral Port Interface
SPI Flash
3.12.1Signal Interface
3.12PCI Interface
PCI Controller Sheet 1 of
3.12.2PCI Interface Block Diagram
PCI Controller Sheet 2 of
3.12.3Supporting 5 V PCI Interface
Figure 16. PCI Interface
Compact PCI Bus
cPCI J1
3.12.4PCI Option Interface
3.3V Logic
PCI Device
PCI Device
Page
3.13JTAG Interface
3.12.5Design Notes
3.13.1Signal Interface
3.14.1Clock Signals
Clock Signals
3.14Input System Clock
3.15Power
3.14.3Device Connection
Intel IXP46X
3.15.5Power Sequence
3.15.6Reset Timing
Power Interface Sheet 2 of
3.15.1De-CouplingCapacitance Recommendations
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4.4Component Placement
4.0General PCB Guide
4.1PCB Overview
4.2General Recommendations
Figure 19. Component Placement on a PCB
4.5Stack-UpSelection
Inexpensive
Medium Frequency
Uncontrolled signal trace impedance
Low-impedancepower distribution
Higher cost More weight
Poor routing density
Figure 20. 8-LayerStackup
Figure 21. 6-LayerStackup
5.0General Layout and Routing Guide
5.1Overview
5.2General Layout Guidelines
Figure 22. Signal Changing Reference Planes
5.2.1General Component Spacing
VIAs
Figure 24. Poor Design Practice for VIA Placement
25 mils min 25 mils min 25 mils min
Flush Via min Potential Bridge min
5.2.2Clock Signal Considerations
PGA or BGA Package
5.2.3SMII Signal Considerations
5.2.4MII Signal Considerations
5.2.5USB Considerations
5.2.6Cross-Talk
5.2.7EMI-DesignConsiderations
5.2.9Power and Ground Plane
5.2.8Trace Impedance
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6.0PCI Interface Design Considerations
6.1Electrical Interface
6.2Topology
6.3Clock Distribution
Figure 26. PCI Address/Data Topology
PCI Slot
Table 25. PCI Address/Data Routing Guidelines
6.3.1Trace Length Limits
PCI Devices
Clock
Driver
6.3.3Signal Loading
6.3.2Routing Guidelines
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DDR Signal Groups
7.0DDR-SDRAM
7.1Introduction
Table
Figure 28. Processor-DDRInterface
Processors
Line of Network
DDR SDRAM
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Supported Memory Configurations
VTT Signal Termination
Signal
Termination
Intel IXP46X
7.1.1Selecting VTT Power Supply
Figure 30. VTT Terminating Circuitry
IXP46X
DDR SDRAM
Figure 31. DDR Command and Control Setup and Hold
Control/Command Valid
DDR M CLK
7.1.2Signal-TimingAnalysis
Figure 32. DDR Data to DQS Read Timing Parameters
Data
DDR Data to DQS Read Timing Parameters
Figure 33. DDR-Data-to-DQS-WriteTiming Parameters
Data Valid
DDR Data to DQS Write Timing Parameters
Data
7.1.3Printed Circuit Board Layer Stackup
DDR-Clock-to-DQS-WriteTiming Parameters
7.1.4Printed Circuit Board Controlled Impedance
Figure 35. Printed Circuit Board Layer Stackup
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7.1.5Timing Relationships
Figure 31 on page -Table 29 on page
—Table 30 on page —Table 31 on page
Figure 32 on page -Table 30 on page
7.1.6Resistive Compensation Register Rcomp
7.1.7Routing Guidelines
7.1.7.1Clock Group
7.1.7.2Data, Command, and Control Groups
Clock Signal Group Routing Guidelines
7.2Simulation Results
7.2.1Clock Group
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7.2.2Data Group
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TL1 Tpd = 175 ps/in
Figure 39. DDR Data Topology Two-Bankx16 Devices
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7.2.3Control Group
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7.2.4Command Group
TL1 Tpd = 175 ps/in
TL2 Tpd = 175 ps/in
TL3 Tpd = 175 ps/in
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7.2.5RCVENIN and RCVENOUT
Figure 49. DDR RCVENIN/RCVENOUT Topology
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Document Number 305261, Revision
