lattice增量编译建议及部分翻译

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1、ThefollowingisalistofgenerallimitationsthatyoushoulduseasaguidelinefordeterminingwhetherornotyourdesignisagoodcandidateforrunningthroughtheIncrementalDesignflow.AlthoughtheIncrementalDesignflowingeneralwillprovideshorterruntimesandarelativelyconsistentresult,therewillbesitu

2、ationsitmaytakelonger.Forexample,insomecasestheincrementalflowmightnotmeettiminggoalswhereasthenormalflowcan.尽管增量编译设计可以减少综合时间并使迭代设计的结果更加相近,在某些情况下反而会带来更长的运行时间.比如当使用增量编译造成时序不容易满足时.TheIncrementalDesignflowissuitableforwell-partitioneddesigns.Aflatdesignoradesignwithmanycritica

3、lpathscrossingpartitionsmayactuallyresultinpoorerperformanceusingtheincrementalflow.增量编译更加适用于模块分布合理的设计.一个flat的设计(应该拥有指过大的模块)或者两个模块间有过多的路径的设计使用增量编译可能导致性能下降.DesignsthathaveaveryhighresourceutilizationmaynotbeagoodcandidatesforrunningintheIncrementalDesignflowbecausetypicallyt

4、hisflowrequiresampleresourceavailability.增量编译需要额外的资源,故资源利用率过高的设计不推荐使用.DesignswithcongestionmayalsonotbegoodcandidatesfortheIncrementalDesignflowforthesamereason,thatis,incrementaldesignstendtorequiremoreresourceavailabilitytoresolvecongestion,suchaslooseplacementanddetourro

5、uting.不理解congestion...阻塞是组合逻辑过多?Thepartitionfloorplanningthatoccursinthisflowcanautomaticallygeneratepartitionconstraints.Acompleteddesignisrequiredtogenerateareasonablepartition.Runningincrementalflowonpartialdesignisnotrecommended.Oftentimestheauto-generatedpartitionconst

6、raintisnotoptimal.Itisstronglyrecommendedthatifyoumustadjustpartitionconstraints,thatyoudosobasedonyourknowledgeofthedesign.Toachievethebeststabilityandquicktimingloopclosure,itisstronglyrecommendedthatyoukeepthechangesfromoneiterationtothenextiterationtoaminimum.Anymajorch

7、angeoralotofminorchangeswillresultinacompletelydifferentresultwhichmayunderminetheoveralleffectivenessoftheincrementaldesignflow’sinherentstrategy.增量编译适用于小的迭代,大的变动会破环其整体效果TheIncrementalDesignflowmayyieldloosepackingandlesserperformanceduetopartitionconstraints.Also,iftheinc

8、rementalrouterisapplied,longerruntimeandworseperformancemayresult,if,fromiteration