User manual CADENCE DESIGN SYSTEMS ENCOUNTER LIBRARY CHARACTERIZER DATASHEET

[. . . ] One of the problems designers face when implementing a power savings strategy or moving to smaller process nodes is the need for numerous, more advanced sets of standard-cell libraries. For ASIC and CoT designers, this can be a real barrier to Power and process variation concerns are growing along with other challenges for digital IC designers. To get the most out of today's large, low-power designs, engineers need advanced modeling formats to support their cutting-edge digital design flows. [. . . ] Two types of logic are state dependent: complex gates: AOI and OAI, and exclusive logic such as XOR and XNOR. During the logic recognition stage, Encounter Library ACCURATE NLDM CHARACTERIZATION The industry-standard Liberty (or . lib) format utilized Non-Linear Delay Models (NLDMs) to estimate delay as a function ofgateinputslewandthenetwork www. cadence. com ENCOUNTER LIBRARY CHARACTERIZER 2 loading on the output. Encounter Library Characterizer accurately generates these models to support synthesis and static timing analysis (STA), and provides a baseline for more advanced modeling formats. ECSM POWER MODEL CHARACTERIZATION Encounter Library Characterizer generates ECSM power inside the . lib format library and enables dynamic or static gate-level power-consumption analysis by characterizing the actual current drawn from the power grid at any given time for individual cells. The extension allows storage of current waveforms at power-grid pins for different combinations of slew and load. ECSM power model characterization: · GeneratesSi2-approvedECSMpower extensions · Characterizesdynamiccurrentsignatures of power and ground pins, represented in ECSM as current waveforms ­ Supportseither2Dor3Dlookup tables ­ Generatespiecewiselinear(PWL) representations of current waveforms · CanincrementallyaddECSMpower extensions to existing . lib · IssupportedbyEncounterPower System and Encounter Timing System ECSM noise model characterization: · GeneratesSi2-approvedECSMnoise extensions · Characterizesfornoisedelayandglitch models ­ Accurately models the driving stage of each gate noise on delay ­ Models the effective holding resistance of the output stage of the cell for glitch analysis · Usesadvancedvoltage-in/voltage-out (ViVo) models that capture the effective cell I-V characteristics ­ Each current model is represented by a ViVo waveform on an input or output pin of a cell ­ 2Dlookuptableisusedtostore values of I (Vi, Vo) · Alsoconsidersinternalpins · IssupportedbyEncounterTiming System and Encounter Digital Implementation System ECSM DELAY MODEL CHARACTERIZATION Modeling the voltage impact on delay can be particularly problematic for low-power applications. The Effective Current Source Model (ECSM) timing model is an advanced cell driver model that represents the effect of non-linear switching waveforms on cell-based interconnect delay calculation. It has consistently demonstrated superior delay calculation accuracy by modeling a cell's output drive as a current source rather than a voltage source. Current sources aremoreeffectiveattrackingnon-linear transistor switching behavior and they permit highly accurate modeling of the complex interconnect common in today's largest low-power nanometer designs. It is also the only approved standard from the Silicon Integration Initiative's Open Modeling Coalition (www. si2. org). ECSM delay model characterization: · Usedforthousandsoftapeoutssince 2001 · Deliversaccuracytowithin2%ofSPICE with non-linear IR drop derating ­ . lib (NLDM) can be off by as much as 20% · IsanSi2-approvedstandard · Offersvoltage-basedcharacterization for greater accuracy and ease of adoption · Supportsmulti-piecepincapmodeling for greater accuracy on short, highfanout nets · WorkswithCadenceEncounterDigital Implementation System, Encounter Timing System, and third-party tools CCS TIMING MODEL CHARACTERIZATION The Composite Current Source (CCS) Model is a new, current-based model similar to ECSM that models current vs. time and multi-piece capacitances to enable more accurate static timing analysis. Encounter Library Characterizer provides efficient CCS characterization, whichpickscurrentwaveformpoints intelligently to maximize accuracy while minimizing library size. ECSM NOISE MODEL CHARACTERIZATION Theriskofsignalintegrity(SI)-related failures in silicon increases greatly at 90nm and below. Using advanced voltage-in/voltage-out relationships, Encounter Library Characterizer can generate ECSM noise extensions to . lib that enable SI analysis technologies such as Encounter Timing System to model the cumulative effects of noise introduced by coupling capacitances in complex scenarios where multi-Vt and multi-voltage devices commingle. The SI extensions are based on the cdB format, which is production-proven in morethan1, 000tapeouts. Whenused in conjunction with power and timing extensions, the noise extensions to ECSM will accurately measure the cumulative impact of IR drop and noise on delay and provide a comprehensive view of timing as well as power signoff. CCS NOISE MODEL CHARACTERIZATION The CCS Noise model provides cell-level noise models to enable support for some noise analysis solutions. Characterization includes: · Current-baseddrivermodel · Receivermodel www. cadence. com ENCOUNTER LIBRARY CHARACTERIZER 3 CCS POWER MODEL CHARACTERIZATION The CCS Power model provides additional information for dynamic and static power analysis similar to that provided by ECSM power. Characterization includes: · DCCurrent · Outputvoltage · NoisePropagation · MillerCapacitance SILICON-ON-INSULATOR SUPPORT Partially depleted Silicon-On-Insulator (SOI) process technology requires special handling during library characterization so that the floating body history effect can be properly modeled during timing analysis. [. . . ] This leads to aggressive overdesign, overcompensation for IR drop, and potentially unnecessary architectural changes. Thesolutionistomodeltheleakage power as a statistical probability to avoid designing to the worst-case limit. This enables designers to target a smaller, morereasonableleakagenumber, which canbeasmuchas40%smallerthanthat fromtraditionalworst-caseleakagepower analysis. Encounter Library Characterizer GXLisfoundry-certifiedforleakagepower characterization using the statistical ECSM format: · State-dependentexponentialleakage power variation with respect to process parameters · Die-to-die, within-the-die(spatially correlated), and random variation STANDARD INTERFACE SUPPORT · Inputs:SPICEsubckt, SPICEmodels, . lib, setup_file (for slew, load, operating condition information), and statistical config file (for parameter variation) · Outputs:. lib+ECSMtiming, noise, power, and statistical formats, and CCS · SimulatorsSupported:CadenceSpectre, Synopsys HSpice, Mentor Eldo CADENCE SERVICES AND SUPPORT · Cadenceapplicationengineerscan answer your technical questions by telephone, email, or Internet--they can also provide technical assistance and custom training · Cadencecertifiedinstructorsteach more than 70 courses and bring their real-world experience into the classroom · Morethan25InternetLearningSeries (iLS) online courses allow you the flexibility of training at your own computer via the Internet ·CadenceOnlineSupportgivesyou 24x7onlineaccesstoaknowledgebase of the latest solutions, technical documentation, software downloads, and more PACKAGING Encounter Library Characterizer is availableinXLandGXLbaselicenses. PLATFORMS · Linux(32-bit, 64-bit) · Solaris(64-bit) · AIX(64-bit) · Sol86(64-bit) www. cadence. com ENCOUNTER LIBRARY CHARACTERIZER 5 For more information contact Cadence sales at: +1. 408. 943. 1234 or log on to: www. cadence. com/ contact_us © 2009 Cadence Design Systems, Inc. [. . . ]