Intel IXP43X manual Signal Type Definitions, Soft Fusible Features Sheet 1, Symbol Description

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

3.0General Hardware Design Considerations

This chapter contains information for implementing and interfacing with major hardware blocks of the Intel® IXP43X Product Line of Network Processors. Such blocks include DDRII/I SDRAM, Flash, Ethernet PHYs, UART and other peripherals interfaces. Signal definition tables list resistor recommendations for pull-ups and pull-downs.

Features disabled by a specific part number, do not require pull-ups or pull-downs. Therefore, all pins can be left unconnected. Features enabled by a specific part number and required to be Soft Fuse-disabled, only require pull-ups or pull-downs in the clock-input signals. Other conditions can require pull-up or pull-down resistors for configuration purposes at power on or reset. In the same way, open-drain outputs must be pulled high.

Warning: With the exception of USB_V5REF all other I/O pins of the IXP43X network processors are not 5.0-V tolerant.

Table 2 gives the legend for interpreting the Type field used in the signal-definition tables that are covered in this chapter.

Table 2. Signal Type Definitions

Symbol

Description

 

 

I

Input pin only

 

 

O

Output pin only

 

 

I/O

Pin can be an input or output

 

 

OD

Open-drain pin

 

 

TRI

Tri-State pin

 

 

PWR

Power pin

 

 

GND

Ground pin

 

 

3.1Soft Fusible Features

Soft Fuse Enable/Disable is a method to enable or disable features in hardware, virtually disconnecting the hardware modules from the processor.

Some of the features offered in the IXP43X product line of network processors can be Soft Fuse Enabled/Disabled during boot. It is recommended that if a feature is not used in the design, the feature be soft disabled. This helps reduce power and maintain the part running at a cooler temperature. When Soft Fuse Disabled, a pull-up resistor must be connected to each clock input pins of the disabled feature interface. All other signals can be left unconnected.

Soft Fuse Enable/Disable can be done by writing to EXP_UNIT_FUSE_RESET register. For more information refer to the Intel® IXP43X Product Line of Network Processors Developer’s Manual and review the register description.

Table 3.

Soft Fusible Features (Sheet 1 of 2)

 

 

 

 

 

 

Name

Description

 

 

 

 

 

 

PCI

The complete bus must be enabled or disable.

 

 

 

 

 

 

HSS0

Can only be disable as a pair.

 

 

 

 

 

 

UTOPIA

while enabling UTOPIA, MACs on NPE A is disabled.

 

 

while enabling MACs on NPE A, UTOPIA is disabled.

 

 

 

 

 

 

 

 

 

Intel® IXP43X Product Line of Network Processors

April 2007

 

 

HDG

Document Number: 316844; Revision: 001US

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Contents Hardware Design Guidelines Intel IXP43X Product Line of Network ProcessorsApril Intel IXP43X Product Line of Network ProcessorsHDG Contents Figures Tables Document Number 316844 Revision 001US 001 Initial release § §Date Revision Description HDG Chapter Name Description Content OverviewAcronyms Related DocumentationList of Acronyms and Abbreviations Sheet 1 Term ExplanationList of Acronyms and Abbreviations Sheet 2 OverviewHDG Intel IXP435 Network Processor Block Diagram Typical Applications System Memory Map System Architecture DescriptionIntel IXP43X Product Signal Type Definitions Soft Fusible FeaturesSoft Fusible Features Sheet 1 Symbol DescriptionUSB Host Each USB can be Enable separately Soft Fusible Features Sheet 2DDRII/I Sdram Interface EthernetDDRII/I Sdram Interface Pin Description Sheet 1 Signal InterfaceType Name Device-Pin Connection Terminatio Description FieldDDRII/I Sdram Interface Pin Description Sheet 2 DDRII/I Sdram InitializationType Pull Name Recommendations Field Down Expansion Bus Signal Recommendations Sheet 1Expansion Bus Expansion Bus Signal Recommendations Sheet 2 Reset Configuration StrapsBoot/Reset Strapping Configuration Sheet 1 Name Type Pull Recommendations Field DownBoot/Reset Strapping Configuration Sheet 2 3 8-Bit Device Interface Setting Intel XScale Processor Operation SpeedIntel XScale Processor Cfg0 Cfg1 Cfgenn Actual Core Speed MHz4 16-Bit Device Interface 16-Bit Device Interface Flash InterfaceFlash Interface Example Uart InterfaceUart Signal Recommendations Uart Interface Example MII InterfaceMII NPE C Signal Recommendations Sheet 1 Signal Interface MIIMII NPE a Signal Recommendations Device Connection, MII MII NPE C Signal Recommendations Sheet 2MAC Management Signal Recommendations NPE a and NPE C MII Interface Example Gpio InterfaceDesign Notes Gpio Signal RecommendationsUSB Interface Name Type Pull Description Field Down USB Host Signal RecommendationsCommon Mode Choke Host Device Type Pull Name Description Field Down Utopia Level 2 InterfaceUtopia Level 2/MIIA UTPOPDATA75 UTPOPDATA4UTPOPADDR40 UtpopfciUtpipfci ClavUtpipsoc ETHARXDATA30 EtharxclkUTPIPDATA6 UTPIPDATA5UTPIPDATA7 UTPIPADDR40Device Connection HSS InterfaceHSSTXDATA0 High-Speed, Serial InterfaceHSSTXCLK0 HSSRXDATA0HSS Interface Example SSP InterfaceSynchronous Serial Peripheral Port Interface Serial Flash and SSP Port SPI Interface Example PCI InterfacePCI Controller Sheet 1 PCI Controller Sheet 2 PCI Interface Block DiagramPciintan PciclkinPCI Option Interface Connect signal to same pin between PCI Parity Two devicesPCI Host/Option Interface Pin Description Sheet 1 Type Option Description Name Device-Pin Connection FieldSignal PCIREQN0 to one PCIREQN30 inputs to the Host On the Option device, these signals are notPCI Host/Option Interface Pin Description Sheet 2 Type Option Name Device-Pin Connection Description FieldPCI Host/Option Interface Pin Description Sheet 3 Jtag InterfaceClock Signals Clock SignalsInput System Clock Clock OscillatorRecommendations for Crystal Selection Nominal Name Voltage Description PowerPower Supply Reset Timing Power SequenceDecoupling Capacitance Recommendations VCC Decoupling§ § PCB Overview Component PlacementGeneral Recommendations Component SelectionStack-Up Selection Component Placement on a PCBControlled-impedance traces Low-impedance power distribution Layer Stackup General Layout Guidelines General Layout and Routing GuideGeneral Component Spacing Signal Changing Reference PlanesGood Design Practice for VIA Hole Placement Pad-to-Pad Clearance of Passive Components to a PGA or BGA Clock Signal ConsiderationsCrosstalk MII Signal ConsiderationsUSB V2.0 Considerations Trace Impedance Power and Ground PlaneEMI Design Considerations § § Topology Electrical Interface@33 MHz Tcyc = 30 nSec Tval = 11 nSec Tprop = 10 nSecParameter Routing Guidelines Clock DistributionPCI Address/Data Routing Guidelines PCI Clock Routing Guidelines Trace Length LimitsRouting Guidelines Signal LoadingIntroduction Ddrii / Ddri SdramGroup Signal Name Description DDRII/I Signal GroupsDrasn / Ddrrasn Dcasn / DdrcasnDDR Sdram Supported Ddrii 32-bit Sdram Configurations Supported Ddri 32-bit Sdram ConfigurationsSupported Ddri 16-bit Sdram Configurations SizeaDDRII/DDRI Rcomp and Slew Resistances Pin Requirements Supported Ddrii 16-bit Sdram ConfigurationsAddress Size Leaf Select Total Technology Arrangement BanksDDR Clock Timings DDR-II Symbol Parameter Units Min MaxDdrii OCD Pin Requirements DDR Sdram Write Timings Symbol Parameter Minimum Nominal Maximum Units DDRII-400 MHz Interface -- Signal TimingsSymbol Parameter Minimum Nom Maximum Units DDR II/I Sdram Interface -- Signal TimingsTiming Relationships Printed Circuit Board Layer StackupTiming Relationships Signal Package Lengths Sheet 1Group Signal Name Length mil Signal Package Lengths Sheet 2 Clock Group Signal Package Lengths Sheet 3Parameter Definition Data and Control GroupsDCB70/DDRCB70, DDQ310 / DDRDQ310 Ddrii Data and Control Signal Group Routing GuidelinesSignal Group Members Ddrii Command Signal Group Routing Guidelines§ §