Intel 440GX manual Matching the Reference Planes, Adding Additional Decoupling Capacitor, Register

Page 47

Motherboard Layout and Routing Guidelines

Figure 2-17. Registered SDRAM DIMM Example

SDRAM

SDRAM

SDRAM

SDRAM

SDRAM

SDRAM

SDRAM

DRAMS

 

Register

 

PLL

Register

 

Data

Control

 

 

Clock

 

 

 

There are also “population” rules which need to be observed. To properly adjust memory timings for 100 MHz operation, it is asked of the OEM and end user to populate the motherboard starting with the DIMM located the furthest from the 82443GX.

2.9.1.1Matching the Reference Planes

Providing a good return path for the AC currents induced on the power and ground planes is critical to reducing signal noise. The best way to provide a low inductance return path is to “match” the BGA and motherboard reference planes for a given signal. For example, MD0 is routed on the BGA next to the ground plane. To “match” the reference planes, MD0 should be routed on the Motherboard such that it is closest to the motherboard ground plane. Routing the memory signals in this manner will provide the best possible path for the return currents.

Table 2-17. MDx lines Reference Planes Routing

Memory Data Line

82443GX BGA

Motherboard

Reference Layer

Reference Plane

 

 

 

 

MD0,MD1,MD2,MD3, MD4, MD7, MD11, MD14,

 

 

MD15, MD16, MD17, MD19, MD20, MD21, MD22,

 

 

MD23, MD27, MD28, MD29, MD31, MD33, MD36,

GND layer

GND plane

MD37, MD38, MD40, MD41, MD42, MD43, MD 44,

 

 

MD45, MD48, MD49, MD52, MD53,MD55, MD56,

 

 

MD 57, MD 58, MD61, MD62, MD63, MECC[6:0]

 

 

 

 

 

MD5, MD6, MD8, MD9, MD10, MD12, MD13, MD18,

 

 

MD24, MD25, MD26, MD30, MD32, MD34, MD35,

3.3v VCC layer

3.3v power plane

MD39, MD46, MD47, MD50, MD51, MD54, MD59,

 

 

MD60, MECC7

 

 

 

 

 

2.9.1.2Adding Additional Decoupling Capacitor

Another way to provide a low inductance path for return currents is to provide additional decoupling capacitors next to signal vias. It is not possible to route all the MD lines on a single layer. As a result, some of the MD lines will transition between signal layers through vias. The return currents associated with these signals also require a low inductance path between Vcc and ground. This low inductance path is provided by decoupling capacitors between Vcc and ground. These decoupling capacitors should be placed as close as possible to the signal vias.

Intel®440GX AGPset Design Guide

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Contents Design Guide Intel 440GX AGPsetIntel440GX AGPset Design Guide Contents 6.5 Dimm Solution With FET SwitchesSystem Bus Clock Layout 6.3 6.482371EB PIIX4E PIIX4E Power And Ground PinsISA and X-Bus Signals Thermals / Cooling Solutions 20.1Intel440GX AGPset Platform Reference Design IntelPentiumII Processor LAI IssueFET Switches4 DIMM/FET Design Voltage Regulator Control SiliconSolution Space for Single Processor Designs With Single-End Example ATX Placement for a UP Pentium II processorExample NLX Placement for a UP Intel Pentium II processor Solution Space for Single Processor Design Based on ResultsMotherboard Model MAB12,11,90#, MAB14,13,10, 4 DIMMs TablesIntel Pentium II Processor and Intel 440GX AGPset Intel Pentium II Processor and Intel 440GX AGPset 100 MHzDate Revision Description Revision HistoryIntel440GX AGPset Design Guide Introduction Page About This Design Guide IntroductionReferences Intel Pentium II Processor Intel Pentium II Processor / Intel 440GX AGPset OverviewVCR Intel 440GX AGPsetAccelerated Graphics Port Interface System Bus InterfaceDram Interface System Clocking Wired for Management InitiativePCI-to-ISA/IDE Xcelerator PIIX4E PCI InterfaceInstrumentation Remote Service BootRemote Wake-Up Power ManagementDesign Recommendations Voltage DefinitionsGeneral Design Recommendations Introduction Motherboard Design Page BGA Quadrant Assignment Major Signal Sections 82443GX Top ViewATX Form Factor NLX Form Factor Board DescriptionFour Layer Board Stack-up Routing Guidelines Single Processor Network Topology and Conditions 1 GTL+ Description2 GTL+ Layout Recommendations Single Processor DesignTrace Minimum Length Maximum Length Single Processor Recommended Trace LengthsRecommended Trace Lengths for Single Processor Design Dual Processor Recommended Trace Lengths Dual Processor SystemsSingle Processor Systems-Single-End Termination SET Dual Processor Network Topology and ConditionsSET Trace Length Requirements SET Trace Length RequirementsPractical Considerations Additional GuidelinesMinimizing Crosstalk Design Methodology 12. GTL+ Design Process Performance RequirementsRecommended 100 MHz System Flight Time Specs Topology DefinitionPre-Layout Simulation Sensitivity Analysis Simulation MethodologyPost-Layout Simulation Placement & LayoutFlight Time Measurement Crosstalk and the Multi-Bit Adjustment FactorValidation Edge Guideline @ Processor Edge Spec @ Processor Core Signal Quality MeasurementTerm Description Timing AnalysisTiming Term Value 10. Recommended 100 MHz System Timing Parameters11. Recommended 100 MHz System Flight Time Specs Timing Term Intel Pentium II Processor Intel 440GX AGPset12. Data and Associated Strobe AGP Connector Up Option Layout GuidelinesConnector AGP Layout and Routing GuidelinesWidthSpace Trace Line Length Line Length Matching 14. Control Signal Line Length RecommendationsOn-board AGP Compliant Device Down Option Layout Guidelines 13. Source Synchronous Motherboard Recommendations15. Source Synchronous Motherboard Recommendations 16. Control Signal Line Length RecommendationsCompliant 82443GX Graphics Data Routing Device To 82443GX MDs & MECCs To DIMM10 DQs To DIMM32 DQs 82443GX Memory Subsystem Layout and Routing Guidelines1 100 MHz 82443GX Memory Array Considerations Register Data Control Clock Matching the Reference PlanesAdding Additional Decoupling Capacitor RegisterTrace Width vs. Trace Spacing Memory Layout & Routing GuidelinesSwitch 16212 Dimm Module 18. FET Switch DQ Route Example82443GX Dimm Module 82443GX 0.6 0.4 0.6 0.4 Dimm Module24. Motherboard Model-DQMB1,5, 4 DIMMs 21. Motherboard Model SCASB#, 4 DIMMs 19. Motherboard Model SRASB#, 4 DIMMs20. Motherboard Model SCASA#, 4 DIMMs 24. Motherboard Model MAA140, 4 DIMMs 22. Motherboard Model WEA#, 4 DIMMs23. Motherboard Model WEB#, 4 DIMMs VCC3 3 4 Dimm Routing Guidelines no FETPCI Bus Routing Guidelines 25. Motherboard Model MAB12,11,90#, MAB14,13,10, 4 DIMMsHost Bridge Controller 492 BGA Decoupling Guidelines Intel 440GX AGPset Platform014 018 Clock Intel 440GX AGPset Clock Layout RecommendationsClock Routing Spacing System Bus Clock Layout440GX Ckbf Dlko PCI Clock LayoutSdram Clock Layout Net Trace Length Min Max CapNet Trace Length Min Max Card Trace AGP Clock LayoutDesign Checklist Page Pull-up and Pull-down Resistor Values OverviewProcessor Pin Pin Connection Intel Pentium II Processor ChecklistSlot Connectivity Sheet 1 Slot Connectivity Sheet 2 Vtt VCC3 Reserved NC Vcc GND & Power Pin DefinitionSlot Connectivity Sheet 3 Intel Pentium II Processor Clocks Intel Pentium II Processor SignalsDesign Checklist Voltage Regulator Module, VRM Uni-Processor UP Slot 1 ChecklistDual-Processor DP Slot 1 Checklist Slot 1 Decoupling CapacitorsSEL100/66# Intel 440GX AGPset Clocks1 CK100 100 MHz Clock Synthesizer Processor Frequency SelectGcke and Dclkwr Connection Ckbf Sdram 1 to 18 Clock BufferGX Connectivity Sheet 1 82443GX Host Bridge1 82443GX Interface GX Connectivity Sheet 2 VTTA, Vttb 2 82443GX GTL+ Bus Interface3 82443GX PCI Interface GX Connectivity Sheet 3Strapping Options Signal Description Register Pulled to ‘0’ Pulled to ‘1’4 82443GX AGP Interface Sdram Connectivity 82443GX Pins/Connection Dimm Pins Pin FunctionIntel 440GX AGPset Memory Interface Sdram ConnectionsRegistered Sdram Dimm Solution With FET SwitchesPIIX4E Connectivity Sheet 1 Signal Names Connection82371EB PIIX4E PIIX4E ConnectionsPIIX4E Connectivity Sheet 2 PIIX4E Connectivity Sheet 3 PIIX4E Connectivity Sheet 4 Motherboard Signal ResistorIDE Routing Guidelines CablingIDE Reset#PDD150 PDA20 Pin32,34PIIX4E PWR & GND PCI Bus SignalsPIIX4E Power And Ground Pins 11. Non-PIIX4E ISA Signals ISA SignalsISA and X-Bus Signals 10. Non-PIIX4E PCI Signals12. Non-PIIX4E IDE USB InterfaceIDE Interface PLCC32 to TSOP40 PLCC32 to PSOP44 PDIP32 to TDIP40 Flash DesignDual-Footprint Flash Design Flash Design ConsiderationsXD70 Write Protection 13. Flash Vpp RecommendationsPower Management Signals System and Test SignalsVCC3 Power Button Implementation Miscellaneous 17 82093AA Ioapic 18.2 LM79 Microprocessor System Hardware Monitor 18.1 Max1617 Temperature SensorManageability Devices Required in both a and B stepping designs 18.3 82558B LOM ChecklistPin Number Pin Name Resistor Value Comment Wake On LAN WOL Header Software/BIOSUSB and Multi-processor Bios Design Considerations Thermals / Cooling SolutionsMechanicals Electricals Design Consideration Layout ChecklistApplications and Add-in Hardware Routing and Board FabricationDebug Recommendations Page In-Target Probe ITP Slot 1 Test ToolsDebug/Simulation Tools Logic Analyzer Interface LAI4 I/O Buffer Models Debug FeaturesIntel Pentium II Processor LAI Issue Bus Functional Model BFM150 ohm 150 330 ohmKohm 430 ohmPICD0# 150 ohm PICD1# Debug Logic RecommendationsA20M# 150 330 ohm Design Considerations Debug ProceduresDebug Layout Debug ConsiderationsDebug Recommendations Third Party Vendors Page Supplier Contact Phone Slot 1 ConnectorProcessors GTL+ Bus Slot 1 Terminator CardsVoltage Regulator Control Silicon Vendors Voltage Regulator ModulesVoltage Regulator Control Silicon Voltage Regulator ModulesClock Drivers Power Management ComponentsFET Switches4 DIMM/FET Design Intel 440GX AGPsetOther Processor Components Reference Design Schematics Page Intel 440GX AGPset Platform Reference Design 82443GX Component System bus and Dram Interfaces VRM Power Connectors Front Panel Jumpers

440GX specifications

The Intel 440GX chipset was launched in 1997 as part of Intel's series of chipsets known as the 440 family, and it served as a critical component for various Pentium II and Pentium III-based motherboard architectures. Specifically designed for the second generation of Intel’s processors, the 440GX delivered enhanced performance and supported a range of important technologies that defined PC architectures of its time.

One of the main features of the Intel 440GX was its support for a 100 MHz front-side bus (FSB), which significantly improved data transfer rates between the CPU and the memory subsystem. This advancement allowed the 440GX to accommodate both the original Pentium II processors as well as the later Pentium III chips, providing compatibility and flexibility for system builders and consumers alike.

The 440GX chipset included an integrated AGP (Accelerated Graphics Port) controller, which supported AGP 2x speeds. This enabled high-performance graphics cards to be utilized effectively, delivering many enhanced graphics capabilities for gaming and multimedia applications. The AGP interface was crucial at the time as it offered a dedicated pathway for graphics data, increasing bandwidth compared to traditional PCI slots.

In terms of memory support, the 440GX could address up to 512 MB of SDRAM, allowing systems built with this chipset to run comfortably with sufficient memory for the era’s demanding applications. The memory controller was capable of supporting both single and double-sided DIMMs, which provided versatility in memory configuration for system builders.

Another notable feature of the Intel 440GX was its support for multi-processor configurations through its Dual Processors support feature. This allowed enterprise and workstation computers to leverage the performance advantages of multiple CPUs, making the chipset suitable for business and professional environments where multitasking and high-performance computing were essential.

On the connectivity front, the chipset supported up to six PCI slots, enhancing peripheral device integration and expansion capabilities. It also included integrated IDE controllers, facilitating connections for hard drives and CD-ROM devices.

Overall, the Intel 440GX chipset represented a balanced combination of performance, flexibility, and technology advancements for its time. Its introduction helped establish a foundation for subsequent advancements in PC technology and set the stage for more powerful computing systems in the years to come.
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