Gpio Interface, Device Connection, Smii | Intel IXP45X, IXP46X

General Hardware Design Considerations—Intel®IXP45X and Intel® IXP46X Product Line of Network Processors

3.5.4Device Connection, SMII

Figure 9. SMII Interface Example

Intel® IXP46X

Product Line

Network Processor

SMII_TXSYNC

SMII_TXDATA

SMII_RXDATA

ETH_MDIO

ETH_MDC

SMII_CLK

10/100

PHY

TXSYNC

TXDATA

RXDATA

VCC (3.3 V)

1.5 KΩ

MDIO

MDC

Magnetics

125MHz

REF CLK

RJ45

SMII Interface

B4103-002

3.6GPIO Interface

The IXP45X/IXP46X network processors provide 16 general-purpose input/output pins for use in generating and capturing application specific input and output signals. Each individual pin can be programmed as either an input or output.

When programmed as an input, GPIO0 through GPIO12 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® IXP45X and Intel® IXP46X Product Line of Network Processors
February 2007	HDD
Document Number: 305261; Revision: 004	35

Image 35

Intel IXP45X, IXP46X manual Gpio Interface, Device Connection, Smii

Contents

February Hardware Design Guidelines HDD Contents 12.1 Figures Tables Control Group Topology Transmission Line Characteristics Date Revision Description Revision History HDD Chapter Name Description Content Overview Title Document # Related Documentation Term Explanation OverviewList of Acronyms and Abbreviations Smii Intel IXP465 Component Block Diagram Dslam Typical Applications System Memory Map System Architecture Description Intel IXP465 Example System Block Diagram Symbol Description Soft Fusible FeaturesSignal Type Definitions DDR Sdram Interface Pin Description Sheet 1 Signal InterfaceSoft Fusible Features DDR-266 Sdram Interface Ddrircomp DDR Sdram Interface Pin Description Sheet 2Ddriwen Ddrircveninn DDR Sdram Initialization Expansion BusDDR Sdram Memory Interface Input Pull Name Recommendations Output Down Reset Configuration StrapsExpansion Bus Signal Recommendations Name Function Description Boot/Reset Strapping Configuration Sheet 1 4 16-Bit Device Interface Boot/Reset Strapping Configuration Sheet 23 8-Bit Device Interface 5 32-Bit Device Interface Bit Device 16/32-Bit Device Interface Byte Enable Flash Interface Example Flash Interface Design Notes Uart InterfaceSram Interface Name Input Pull Recommendations Output Down Uart Signal Recommendations Uart Interface Example MII/SMII Interface MII NPE B Signal Recommendations Sheet 1 Signal Interface MIIMII NPE a Signal Recommendations MII NPE C Signal Recommendations MII NPE B Signal Recommendations Sheet 2 NPE A,B,C MAC Management Signal Recommendations NPE A,B,CDevice Connection, MII Smii Signal Recommendations NPE A, B, C Signal Interface, Smii Device Connection, Smii Gpio Interface Gpio Signal Recommendations Device Connection I2C Signal RecommendationsI2C Interface I2C Eeprom Interface Example USB Interface USB Host/Device Signal Recommendations Host Device USB Device Interface Example Utopia Level 2 Interface Utopia Signal Recommendations Utopia Interface Example HSS Interface HSSRXDATA0 High-Speed, Serial InterfaceHSSTXDATA0 HSSTXCLK0 HSSRXCLK1 HSSTXDATA1HSSTXCLK1 HSSRXDATA1 HSS Interface Example SSP Interface Synchronous Serial Peripheral Port Interface Input Pull Name Outpu Recommendations Down PCI InterfacePCI Controller Sheet 1 PCI Controller Sheet 2 PCI Interface Block Diagram PCI Interface Supporting 5 V PCI Interface PCI Host/Option Interface Pin Description Sheet 1 PCI Option Interface PCI Host/Option Interface Pin Description Sheet 2 PCI Host/Option Interface Pin Description Sheet 3 Jtag Interface Clock Oscillator Clock SignalsClock Signals Input System Clock Name Nominal Description Voltage PowerPower Interface Sheet 1 VCC De-Coupling Power SequenceReset Timing De-Coupling Capacitance Recommendations HDD HDD Component Selection Component PlacementPCB Overview General Recommendations Stack-Up Selection Component Placement on a PCB Controlled-impedance traces Low-impedance power distribution Layer Stackup General Layout Guidelines General Layout and Routing Guide General Component Spacing Signal Changing Reference Planes Good Design Practice for VIA Hole Placement Pad-to-Pad Clearance of Passive Components to a PGA or BGA Clock Signal Considerations USB Considerations Smii Signal ConsiderationsMII Signal Considerations EMI-Design Considerations Cross-Talk Trace Impedance Power and Ground Plane HDD @66 MHz Electrical InterfaceTopology @33 MHz Parameter Routing Guidelines Clock DistributionPCI Address/Data Routing Guidelines PCI Clock Routing Guidelines Trace Length Limits Routing Guidelines Signal Loading DDRIDQS40 DDR Signal GroupsGroup Signal Name Description No of Single Ended Signals Introduction DDR Sdram HDD Clock Banks Memory Size Supported Memory Configurations VTT VTT Terminating Circuitry Selecting VTT Power Supply Ddrmclk DDR Command and Control Setup and Hold ValuesSymbol Parameter Min Max Units DDR Data to DQS Read Timing Parameters DDR Data to DQS Write Timing Parameters DDR-Data-to-DQS-Write Timing Parameters Printed Circuit Board Layer Stackup Printed Circuit Board Layer Stackup Printed Circuit Board Controlled Impedance Printed Circuit Board Controlled Impedance Timing Relationships Signal Group Absolute Minimum Absolute Maximum LengthTiming Relationships Clock Group Resistive Compensation Register Rcomp DDRIBA10, DDRIRASN, DDRICASN, Ddriwen Clock Signal Group Routing GuidelinesData, Command, and Control Group Routing Guidelines Parameter Definition Transmission Line Length Clock Group Topology Transmission Line CharacteristicsSimulation Results Clock Group DDR Clock Topology Two-Bank x16 Devices DDR Clock Simulation Results Two-Bank x16 Devices Data Group Data Group Topology Transmission Line Characteristics DDR Data Topology Two-Bank x16 Devices DDR Data Write Simulation Results Two-Bank x16 Devices HDD HDD Control Group Control Group Topology Transmission Line Characteristics DDR RAS Simulation Results Two-Bank x16 Devices Command Group Topology Transmission Line Characteristics Command Group DDR Command MA3 Topology Two-Bank x16 Devices DDR Address Simulation Results Two-Bank x16 Devices DDR Command RAS Topology Two-Bank x16 Devices 104 DDR RCVENIN/RCVENOUT Topology Rcvenin and Rcvenout DDR RCVENIN/RCVENOUT Simulation Results Rseries = 0 Ω DDR RCVENIN/RCVENOUT Simulation Results Rseries = 60 Ω 108