Intel IXP43X manual Ddrii Data and Control Signal Group Routing Guidelines

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

internal layers, except for pin escapes. It is recommended that pin escape vias be located directly adjacent to the ball pads on all signals. Surface layer routing should be minimized. The following table provides routing guidelines for signals within these groups.

Figure 33. DDRII Data and Control Simulation Results: DQ and DQS signals

DQ

22 ohm

DQS

Table 35. DDRII Data and Control Signal Group Routing Guidelines

Parameter	Definition

	D_CB[7:0]/DDR_CB[7:0], D_DQ[31:0] / DDR_DQ[31:0],
Signal Group Members	D_DQS[4:0]/DDR_DQS[4:0], D_DM[4:0]/DDR_DM[4:0].,
	D_CS[1:0]/DDR_CS[1:0] and D_CKE[1:0]/DDR_CKE[1:0]

Topology	Differential Pair Point to Point (1 Driver, 2 Receivers)

Single Ended Trace Impedance (Zo)	50 Ω
Series Resistor	22 Ω

Nominal Trace Width1	Internal (Strip Line) 3.5 mils, External (Micro Strip) 5 mils
Nominal Pair Spacing (edge to edge) 2	Internal (Strip Line) 10.5 mils, External (Micro Strip) 10 mils
Minimum Pair to Pair Spacing	Any layer 20mils

Notes:

1.Nominal trace width is determined by board physical characteristics and stack-up. This value should be verified with the PWB manufacturer to achieve the desired Zo.

2.Nominal pair to pair spacing is determined by board physical characteristics and stack-up. This value should be verified with the PWB manufacturer to achieve the desired Zdiff.

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

Image 84

Contents Intel IXP43X Product Line of Network Processors Hardware Design GuidelinesIntel IXP43X Product Line of Network Processors HDGApril Contents Figures Tables Document Number 316844 Revision 001US § § Date Revision Description001 Initial release HDG Content Overview Chapter Name DescriptionRelated Documentation AcronymsList of Acronyms and Abbreviations Sheet 1 Term ExplanationOverview List of Acronyms and Abbreviations Sheet 2HDG Intel IXP435 Network Processor Block Diagram Typical Applications System Architecture Description System Memory MapIntel IXP43X Product Soft Fusible Features Signal Type DefinitionsSoft Fusible Features Sheet 1 Symbol DescriptionSoft Fusible Features Sheet 2 USB Host Each USB can be Enable separatelyDDRII/I Sdram Interface EthernetSignal Interface DDRII/I Sdram Interface Pin Description Sheet 1Type Name Device-Pin Connection Terminatio Description FieldDDRII/I Sdram Initialization DDRII/I Sdram Interface Pin Description Sheet 2Expansion Bus Signal Recommendations Sheet 1 Expansion BusType Pull Name Recommendations Field Down Reset Configuration Straps Expansion Bus Signal Recommendations Sheet 2Boot/Reset Strapping Configuration Sheet 1 Name Type Pull Recommendations Field DownBoot/Reset Strapping Configuration Sheet 2 Setting Intel XScale Processor Operation Speed 3 8-Bit Device InterfaceIntel XScale Processor Cfg0 Cfg1 Cfgenn Actual Core Speed MHz4 16-Bit Device Interface Flash Interface 16-Bit Device InterfaceUart Interface Flash Interface ExampleUart Signal Recommendations MII Interface Uart Interface ExampleSignal Interface MII MII NPE a Signal RecommendationsMII NPE C Signal Recommendations Sheet 1 MII NPE C Signal Recommendations Sheet 2 MAC Management Signal Recommendations NPE a and NPE CDevice Connection, MII Gpio Interface MII Interface ExampleGpio Signal Recommendations USB InterfaceDesign Notes USB Host Signal Recommendations Name Type Pull Description Field DownCommon Mode Choke Host Device Utopia Level 2 Interface Utopia Level 2/MIIAType Pull Name Description Field Down UTPOPDATA4 UTPOPDATA75UTPOPADDR40 UtpopfciClav UtpipfciUtpipsoc ETHARXDATA30 EtharxclkUTPIPDATA5 UTPIPDATA6UTPIPDATA7 UTPIPADDR40HSS Interface Device ConnectionHigh-Speed, Serial Interface HSSTXDATA0HSSTXCLK0 HSSRXDATA0SSP Interface HSS Interface ExampleSynchronous Serial Peripheral Port Interface PCI Interface Serial Flash and SSP Port SPI Interface ExamplePCI Controller Sheet 1 PCI Interface Block Diagram PCI Controller Sheet 2Pciintan PciclkinConnect signal to same pin between PCI Parity Two devices PCI Option InterfacePCI Host/Option Interface Pin Description Sheet 1 Type Option Description Name Device-Pin Connection FieldOn the Option device, these signals are not Signal PCIREQN0 to one PCIREQN30 inputs to the HostPCI Host/Option Interface Pin Description Sheet 2 Type Option Name Device-Pin Connection Description FieldJtag Interface PCI Host/Option Interface Pin Description Sheet 3Clock Signals Clock SignalsInput System Clock Clock OscillatorRecommendations for Crystal Selection Power Power SupplyNominal Name Voltage Description Power Sequence Reset TimingDecoupling Capacitance Recommendations VCC Decoupling§ § Component Placement PCB OverviewGeneral Recommendations Component SelectionComponent Placement on a PCB Stack-Up SelectionControlled-impedance traces Low-impedance power distribution Layer Stackup General Layout and Routing Guide General Layout GuidelinesSignal Changing Reference Planes General Component SpacingGood Design Practice for VIA Hole Placement Clock Signal Considerations Pad-to-Pad Clearance of Passive Components to a PGA or BGAMII Signal Considerations USB V2.0 ConsiderationsCrosstalk Power and Ground Plane EMI Design ConsiderationsTrace Impedance § § Electrical Interface Topology@33 MHz Tcyc = 30 nSec Tval = 11 nSec Tprop = 10 nSecClock Distribution PCI Address/Data Routing GuidelinesParameter Routing Guidelines Trace Length Limits PCI Clock Routing GuidelinesSignal Loading Routing GuidelinesDdrii / Ddri Sdram IntroductionDDRII/I Signal Groups Group Signal Name DescriptionDrasn / Ddrrasn Dcasn / DdrcasnDDR Sdram Supported Ddri 32-bit Sdram Configurations Supported Ddrii 32-bit Sdram ConfigurationsSupported Ddri 16-bit Sdram Configurations SizeaSupported Ddrii 16-bit Sdram Configurations DDRII/DDRI Rcomp and Slew Resistances Pin RequirementsAddress Size Leaf Select Total Technology Arrangement BanksDDR-II Symbol Parameter Units Min Max Ddrii OCD Pin RequirementsDDR Clock Timings DDR Sdram Write Timings DDRII-400 MHz Interface -- Signal Timings Symbol Parameter Minimum Nominal Maximum UnitsDDR II/I Sdram Interface -- Signal Timings Symbol Parameter Minimum Nom Maximum UnitsTiming Relationships Printed Circuit Board Layer StackupSignal Package Lengths Sheet 1 Group Signal Name Length milTiming Relationships Signal Package Lengths Sheet 2 Signal Package Lengths Sheet 3 Clock GroupData and Control Groups Parameter DefinitionDdrii Data and Control Signal Group Routing Guidelines DCB70/DDRCB70, DDQ310 / DDRDQ310Ddrii Command Signal Group Routing Guidelines Signal Group Members§ §