集成电路设计-09-版图设计.ppt

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1、集成电路设计第九章版图设计1EIS-WuhanUniversityoutlineFloor-PlanningBlockPlacement.GlobalRouting.SwitchboxRouting.2EIS-WuhanUniversity布图规划Floorplanning输入层次化网表描述模块间的互联，模块内逻辑单元及互联逻辑网表—物理描述的转换。布置模块、焊盘、电源、时钟。3EIS-WuhanUniversitydatapathRAMstdcellfloorplanblocks4EIS-WuhanUniversityFl

2、oorplanningstrategiesFloorplanningmusttakeintoaccountblocksofvaryingfunction,size,shape.Mustdesign:spaceallocation;signalrouting;powersupplyrouting;clockdistribution.5EIS-WuhanUniversityPurposesoffloorplanningEarlyindesign:Prepareafloorplantobudgetarea,wirearea/del

3、ay.Tradeoffsbetweenblockscanbenegotiated.Lateindesign:Makesurethepiecesfittogetherasplanned.Implementthegloballayout.6EIS-WuhanUniversityPlaceandRoute7EIS-WuhanUniversityLayoutsynthesisTwocriticalphasesoflayoutdesign:placementofcomponentsonthechip;routingofwiresbet

4、weencomponents.Placementandroutinginteract,butseparatinglayoutdesignintophaseshelpsusunderstandtheproblemandfindgoodsolutions.8EIS-WuhanUniversity布局Placement根据布图规划，布置模块内逻辑单元。目标：可布线最小延迟最小尺寸最小电压衰减9EIS-WuhanUniversityPlacementmetricsQualitymetricsforlayout:area;delay.

5、Areaanddelaydeterminedinpartbywiring.Howdowejudgeaplacementwithoutwiring?Estimatewirelengthwithoutactuallyperformingrouting.10EIS-WuhanUniversityWirelengthasaqualitymetricbadplacementgoodplacement11EIS-WuhanUniversityWirelengthmeasuresEstimatewirelengthbydistancebe

6、tweencomponents.Possibledistancemeasures:Euclideandistance(sqrt(x2+y2));Manhattandistance(x+y).Multi-pointnetsmustbebrokenupintotreesforgoodestimates.12EIS-WuhanUniversityPlacementtechniquesCanconstructaninitialsolution,improveanexistingsolution.Pairwiseinterchange

7、isasimpleimprovementmetric:Interchangeapair,keeptheswapifithelpswirelength.Heuristicdetermineswhichtwocomponentstoswap.13EIS-WuhanUniversityPlacementbypartitioningWorkswellforcomponentsoffairlyuniformsize.Partitionnetlisttominimizetotalwirelengthusingmin-cutcriteri

8、on.Partitioningmaybeinterpretedas1-Dor2-Dlayout.14EIS-WuhanUniversityMin-cutbisectingpartitioningpartition1partition2ABCD3nets1net15EIS-WuhanUniv