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Intel manual GPIO Interface, Network Processors, 10/100, Intel IXP43X

Models: IXP43X

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Network Processors

Intel® IXP43X Product Line of Network Processors—Hardware Design Guidelines

Figure 6. MII Interface Example

	Intel® IXP43X
	Product Line of
	Network Processors	10/100
		10/100
		PHY
	ETH_TXEN	TXEN
	ETH_TXCLK	TXCLK
	ETH_TXDATA[3:0]	TXDATA[3:0]
	ETH_RXDV	RXDV	Magnetics	RJ45
	ETH_RXCLK	RXCLK	Magnetics	RJ45
	ETH_RXCLK	RXCLK
	ETH_RXDATA[3:0]	RXDATA[3:0]
	ETH_COL	COL	25 MHz
	ETH_CRS	CRS
		VCC (3.3 V)
		1.5 KΩ
	ETH_MDIO	MDIO
	ETH_MDC	MDC
	MII Interface
				B4101 -004

3.6GPIO Interface

The IXP43X network processors provide 16 general-purpose input/output pins to generate and capture application-specific input and output signals. Each individual pin can be programmed as an input or output.

When programmed as an input, GPIO 0 to GPIO 12 can be configured to be an interrupt source. Interrupt sources can be configured to detect either active high, active low, rising edge, falling edge, or transitional. In addition, GPIO14 and GPIO15 can be programmed to provide a user-programmable clock out.

During reset, all pins are configured as inputs and remain in this state until configured otherwise, with the exception of GPIO15, which by default provides a clock output. The driver strength of GPIO pins is sufficient to drive external LEDs with a proper limiting resistor.

Intel® IXP43X Product Line of Network Processors
HDG	April 2007
32	Document Number: 316844; Revision: 001US

Image 32

Intel manual GPIO Interface, Network Processors, 10/100, Intel IXP43X

Contents

April Hardware Design GuidelinesIntel IXP43X Product Line of Network Processors Intel IXP43X Product Line of Network Processors AprilContents IntroductionFigures Tables DDRII Data and Control Simulation Results DQ and DQS signalsMAC Management Signal Recommendations NPE A and NPE C Pad-to-Pad Clearance of Passive Components to a PGA or BGADDR Clock Timings Revision History AprilDocument Number 316844 Revision 001US Intel IXP43X Product Line of Network ProcessorsApril 1.1 Content Overview 1.0 Introduction1.2 Related Documentation 1.3 AcronymsIntel IXP43X Product Line of Network Processors Datasheet Intel IXP400 Software Specification Update1.4 Overview Table 1. List of Acronyms and Abbreviations Sheet 2 of16 GPIO General Purpose Input Output Packaging 460-pin PBGA Figure 1. Intel IXP435 Network Processor Block Diagram 1.5 Typical Applications 2.2 System Memory Map 2.0 System Architecture2.1 System Architecture Description JTAG HeaderProcessors Memory Bus3.1 Soft Fusible Features 3.0 General Hardware Design ConsiderationsTable 2. Signal Type Definitions Soft Fusible Features Sheet 1 of3.2 DDRII/I SDRAM Interface Soft Fusible Features Sheet 2 of3.2.1 Signal Interface DDRII/I SDRAM Interface Pin Description Sheet 1 of3.2.2 DDRII/I SDRAM Initialization DDRII/I SDRAM Interface Pin Description Sheet 2 ofExpansion Bus Signal Recommendations Sheet 1 of 3.3.1 Signal Interface3.3 Expansion Bus Boot/Reset Strapping Configuration Sheet 1 of 3.3.2 Reset Configuration StrapsExpansion Bus Signal Recommendations Sheet 2 of Boot/Reset Strapping Configuration Sheet 2 of Network Processors Developer’s Manual3.3.3 8-Bit Device Interface Setting Intel XScale Processor Operation SpeedDocument Number 316844 Revision 001US 3.3.4 16-Bit Device InterfaceApril Byte Access 16-Bit-Word AccessIntel IXP43X Product Line of NetworkIntel Flash 3.4 UART Interface16-Bit-Word Access 16-Bit Device3.4.1 Signal Interface UART Signal RecommendationsConnector Female 1 DCD2 RX 3 TX3.5.1 Signal Interface MII MII NPE A Signal RecommendationsMII NPE C Signal Recommendations Sheet 1 of being disabled without asserting a system reset3.5.2 Device Connection, MII MII NPE C Signal Recommendations Sheet 2 ofMAC Management Signal Recommendations - NPE A and NPE C being disabled without asserting a system reset3.6 GPIO Interface Network Processors10/100 Intel IXP43X3.6.1 Signal Interface 3.7 USB Interface3.6.2 Design Notes GPIO Signal Recommendations3.7.1 Signal Interface USB Host Signal RecommendationsFigure 7. Common Mode Choke USB RBIASP USB RBIASN22.6 Ω ±1 % resistorUTOPIA Level 2/MIIA 3.8.1 Signal Interface3.8 UTOPIA Level 2 Interface Type PullName DescriptionType PullName DescriptionType PullName Description3.9 HSS Interface 3.8.2 Device ConnectionIntel IXP43X Product Line of3.9.1 Signal Interface 3.9.2 Device Connectionbeing disabled without asserting a system reset High-Speed, Serial Interface3.10 SSP Interface Figure 11. HSS Interface ExampleSynchronous Serial Peripheral Port Interface 3.10.1 Signal Interface3.10.2 Device Connection 3.11 PCI Interface Intel IXP43X ProductLine of Network Processors3.11.1 Signal Interface PCI Controller Sheet 1 of3.11.2 PCI Interface Block Diagram PCI Controller Sheet 2 of3.11.3 PCI Option Interface Network ProcessorsFigure 13. PCI Interface Table 18. PCI Host/Option Interface Pin Description Sheet 1 ofPCI Host/Option Interface Pin Description Sheet 2 of TypeOption NamePCI Host/Option Interface Pin Description Sheet 3 of 3.12 JTAG Interface3.11.4 Design Notes 3.12.1 Signal Interface 3.13.1 Clock Signals3.13 Input System Clock 3.13.2 Clock OscillatorNetwork 3.13.3 Recommendations for Crystal SelectionOSCIN 33 KΩ3.14 Power Power SupplyProcessors Datasheet Processors Datasheet3.14.5 Power Sequence 3.14.6 Reset Timing3.14.1 Decoupling Capacitance Recommendations 3.14.2 VCC DecouplingThe IXP43X network processors can be configured at reset de-assertion via external, pull-down resistors on the address expansion bus signals EXADDR2321. For a complete description, see Section 6, “Boot/Reset Strapping Configuration” on page 4.4 Component Placement 4.0 General PCB Guide4.1 PCB Overview 4.2 General Recommendations4.5 Stack-Up Selection InexpensiveManufactured by virtually all printed-circuit-board vendors Figure 16. Component Placement on a PCBPoor routing density Uncontrolled signal trace impedance Lack of power/ground planes, resulting in unacceptable crosstalkControlled-impedance traces Low-impedance power distribution Higher cost More weight Manufactured by fewer vendorsFigure 17. 8-Layer Stackup Figure 18. 6-Layer Stackup5.2 General Layout Guidelines 5.0 General Layout and Routing Guide5.1 Overview Figure 19. Signal Changing Reference Planes VIAs5.2.1 General Component Spacing Figure 20. Good Design Practice for VIA Hole Placement Figure 21. Poor Design Practice for VIA Placement25 mils min 25 mils min 25 mils min Flush Via min Potential Bridge minFigure 22. Pad-to-Pad Clearance of Passive Components to a PGA or BGA 5.2.2 Clock Signal ConsiderationsPBGA Package 5.2.5 Crosstalk 5.2.3 MII Signal Considerations5.2.4 USB V2.0 Considerations 5.2.7 Trace Impedance 5.2.8 Power and Ground Plane5.2.6 EMI Design Considerations Use at least one decoupling capacitor per power pin and place it as close as possible to the pin 6.2 Topology 6.0 PCI Interface Design Considerations6.1 Electrical Interface 6.3 Clock Distribution PCI SlotPCI Slot PCI Slot6.3.1 Trace Length Limits PCI DevicesClock DriverThis manual does not repeat all the guidelines that are already stated in the 6.3.3 Signal Loading6.3.2 Routing Guidelines 7.0 DDRII / DDRI SDRAM 7.1 IntroductionDDRII/I Signal Groups Signal NameGroup DescriptionDDR SDRAM ProcessorsProduct Line of Network IXP43XSupported DDRI 16-bit SDRAM Configurations Supported DDRI 32-bit SDRAM ConfigurationsSupported DDRII 32-bit SDRAM Configurations DDRI R1 =387 Ω ±1 % resistorR 1 = 285 Ω ±1 % resistor DDRIMPCRES7.3 DDRII OCD Pin Requirements 7.3.1 Signal-Timing AnalysisFigure 27. DDRII OCD Pin Requirements Figure 28. DDR Clock Timing WaveformFigure 29. DDR SDRAM Write Timings Figure 30. DDR SDRAM Read TimingsADDR/CTRL CS10# CK DQS DQS # DQSee Figure 29, “DDR SDRAM Write Timings” on page DDRII-400 MHz Interface -- Signal TimingsFigure 31. DDR - Write Preamble/Postamble Duration 7.3.1.0.1 Printed Circuit Board Layer Stackup 7.3.2 Timing RelationshipsDDR II/I SDRAM Interface -- Signal Timings Signal Package Lengths Sheet 1 of Table 31 on pageTable 32 on page Table 33 on page Figure 30 on page Table 32 on pageSignal Package Lengths Sheet 2 of Signal NameSignal Name GroupSignal Package Lengths Sheet 3 of 7.3.3 Routing Guidelines7.3.3.1 Clock Group Clock Signal Group Routing Guidelines 7.3.3.2 Data and Control GroupsFigure 32. DDRII Clock Simulation Results CK Signals 22 ohm Table 35. DDRII Data and Control Signal Group Routing Guidelines7.3.3.3 Command Groups 20ohmTable 35. DDRII Data and Control Signal Group Routing Guidelines Figure 34. DDRII Command Simulation Results ADDRESS signalsTable 36. DDRII Command Signal Group Routing Guidelines