The primetime sta solution provides designers with extensive timing analysis checks, on chip variation analysis techniques, golden delay calculation, advanced modeling, unmatched productivity and easeofuse, a graphical user interface and industrywide asic vendor signoff and foundry support. Our backoftheenvelope calculations had led us to expect that the sram on the chip would cause only 10 to 20 percent of the chiptochip variation in signalprocessing speed. Nominal delays of the logic gates as per characterization are calculated and some pessimism is applied above that to see if there will be any setup andor hold violation at the target frequency. Aocv abbreviation stands for advanced onchip variation. Ocv model is set of commands used during static timing analysis, whereas aocv. Guaranteeing silicon performance with fpga timing models. When a participant crosses the finish line, the rfid tag is read by an rfid reader which transmits the tags id to the timing software. This sdf can be used in a static timer to determine the impact of the on chip temperature profile on full chip timing.
Digital designers typically simulate circuits at extreme process corners for timing sign off. Apr 11, 2019 powerrelated issues are beginning to clash with process variation at 75nm, making timing closure more difficult and resulting in respins caused by unexpected errors and poor functional yield. In traditional ocv analysis, the static timing analyzer takes a conservative. Removing pessimism and optimism in timing analysis ee times. Variability is becoming particularly troublesome at advanced nodes, and there are multiple causes of that variability. Dec 28, 2017 motivation understand sources of variations timing corners modeling onchip variation design margining signoff criterion embedded hyperlinks for an indepth study 4. P, anovas patent technology, to analyze circuit timing and leakage power variation at the transistor level. Topics covered in static timing analysis sta companies works in vlsi.
The proposed methodology requires relative delay and parasitic variations of cells and interconnects. It features comprehensive timing checking and reports, a builtin delay calculator, multiple supply voltage. Aocv is an evolutionary approach to more accurately model increasing variations at 90nanometer nm and 65nm process nodes compared to traditional onchip variation analysis. Addressing process variation and reducing timing pessimism at 16nm and below by ahmed elzeftawi, sr. Lvfliberty variation format is a good solution for challenge1. Consequently, designers add significant timing margin to safeguard their designs against timing violations.
Static timing analysis of a design is performed to estimate its working frequency after the design has been fabricated. Manufacturing process crystal growth ingot silicon cylinder wafers chips 6. Support analysis at 65 nanometers and below, process traditional sta accounts for process withinthedie, dietodie, and random control becomes very difficult. What is the abbreviation for advanced onchip variation. What is the abbreviation for advanced on chip variation. Scope of variation interdie variation intradie variation as an asic vendor we must ensure that our chips work across this range of variation this is a very restrictive condition and will be responsible for many conservative assumptions throughout timing analysis % n.
Aocv abbreviation stands for advanced on chip variation. Each arc timing is then calculated statistically as the total of the nominal delay and the variation. Technologies that offer variation tolerance boost design performance and productivity. Nominal delays of the logic gates as per characterization are calculated and some pessimism is applied above that to see if there will be any setup andor hold violation at the target. When a participant crosses the finish line, the rfid tag is read by an rfid reader which transmits the tags id to. Jul 27, 2009 the software is using stochastic analysis process s. More accurate static timing analysis at advanced nodes the. This is necessitating the use of advanced margining approaches, which are no longer optional, such as advanced parametric on chip variation pocv margining solutions, as well as extended timing noise variation models. This analysis is coming from people who got interviewed and recruited into leading. Synopsys primetime advanced onchip variation analysis enables. Motivation understand sources of variations timing corners modeling onchip variation design margining signoff criterion embedded hyperlinks for an indepth study 4. Sep 25, 2015 and on chip variation ocv is one of them, specifically for static timing analysis interview.
Principal product manager, and ken tseng, software engineering group director, cadence at 16nm and below, on chip variation ocv becomes a critically important issue. Timing engineers must remove any undue pessimismoptimism in the calculation of clock path delay because it can be detrimental for the design. Aug 24, 2015 onchip variation ocv static timing analysis of a design is performed to estimate its working frequency after the design has been fabricated. Oct 01, 2014 the liberty technical advisory board ltab, an ieeeisto federation member program, approved extensions to cover modeling techniques such as advanced on chip variation aocv, parametric on chip variation pocv and statistical on chip variation socv. While it offered accuracy and simplicity, chip timing was labeled by some as too expensive. On chip variation ocv is an increasing problem that starts at nm and its effects are increasing with smaller process nodes.
Onchip variation ocv has become a larger problem at advanced nodes 16nm and below with respect to its impact on timing. Timecraft is a fullchip, gatelevel sta for timing signoff. Use the timing analyzer gui or commandline interface to constrain, analyze, and report results for all timing. And onchip variation ocv is one of them, specifically for static timing analysis interview. A parametric approach for handling local variation effects. Advanced onchipvariation timing analysis for nanometer designs. Lvf includes delay variation is modeled as a function of input transition and output load per timing arc. Historically, as well as operating temperature, timing variation was primarily a consequence of subtle shifts in manufacturing conditions that would lead to ics from one batch of wafers being slow or fast relative to nominal estimates. While previous works ignore the stress and mobility. Parametric onchip variation pocv analysis in synopsys primetimer timing analysis and signoff solution has been enhanced to accurately capture increased nonlinear. This analysis is coming from people who got interviewed and recruited into leading vlsi industries. Most importantly, my posts and videos have helped most of them and i really feel proud about it. Time sta solution provides designers with extensive timing analysis checks, on chip variation analysis techniques, golden delay calculation, advanced modeling, unmatched productivity and ease of use, a graphical user interface, and industry wide asic vendor signoff and foundry support.
So we decided to have it in 3 parts and this is part i essential timing checks. Jul 31, 2009 a parametric approach for handling local variation effects in timing analysis abstract. Timing analysis with onchip variation for cell delays, the onchip variation is between 5 percent above and 10 percent. A parametric approach for handling local variation effects in timing analysis.
And on chip variation ocv is one of them, specifically for static timing analysis. This is necessitating the use of advanced margining approaches, which. Technologies that offer variation tolerance boost design performance and. Within that, we will cover timing, noise, power and variation as 4 main topics of the characterization. A parametric approach for handling local variation effects in. It features comprehensive timing checking and reports, a builtin delay calculator, multiple supply voltage analysis, multitask capability for multicorner and multimode analysis, and advanced phaselocked loop pll handling, which enable the. As variations by introducing more aggressive variation support a result.
It delivers hspice accurate signoff analysis that helps pinpoint problems prior to tapeout thereby reducing risk, ensuring design integrity, and lowering the cost of design. Principal product manager, and ken tseng, software. The pocv method has been implemented in a timing analysis software, and. Effect of statistical clock skew variations on chip timing. For this reason, a module in the intel quartus prime. Page 5 comprehensive variation statistical static timing features of encounter timing system ssta include. Cadence encounter timing system datasheet pdf download. Oct 01, 2018 parametric on chip variation pocv analysis in synopsys primetimer timing analysis and signoff solution has been enhanced to accurately capture increased nonlinear variation due to process.
Oct 01, 2019 rfid chip timing systems accomplish this in a very elegant way. Synopsys primetime advanced ocv technology provides more. Addressing process variation and reducing timing pessimism. Static timing analysis comprises broadly for timing checks, constraints and library. Principal product manager, and ken tseng, software engineering.
Aocv is an evolutionary approach to more accurately model increasing variations at 90nanometer nm and 65nm process nodes compared to traditional on chip variation analysis and is an intermediate step to full statistical timing analysis of variations. Download free prime time synopsys tool software blogsemail. Anovas variation analysis software included in tsmc. Designers assumed the cells to be at the worst or bestcase corner. Scope of variation interdie variation intradie variation as an asic vendor we must ensure that our chips work across this range of variation this is a very restrictive condition and will be. Variation in delay is becoming larger than nominal delay at lower voltages, and nonlinear effects are becoming worse. There are various methodologies to address variation.
Elastic compute and big data tackle fpga chip complexity. It is worthy to point out that ocv derating methodology makes following. Liberty changes bring together nanometer ocv techniques. Support analysis at 65 nanometers and below, process. Timecraft is a full chip, gatelevel sta for timing signoff. Effect of statistical clock skew variations on chip timingyield. For the timing impact analysis, temperaturedependent and voltagedependent delay information of the devices is needed to generate a modified sdf. Using simple derate tables to complement the global derate methodology that has been used for many years to account for on chip variation allows primetime customers to take advantage of the more finelytuned design margins with minimal changes to existing timing signoff scripts.
Synopsys improves signoff accuracy for advanced soc. And on chip variation ocv is one of them, specifically for static timing analysis interview. In this paper we propose a new methodology, called parametric on chip variation pocv analysis, to determine local process variation effects on the timing of designs. Having all of them in a single course makes it bulky. Us9245071b2 database based timing variation analysis. Powerrelated issues are beginning to clash with process variation at 75nm, making timing closure more difficult and resulting in respins. An introduction to onchip variation ocv anysilicon. The software is using stochastic analysis process s. An accepted trend in the semiconductor industry, where process geometry is continuously shrinking, is the growing impact of variation in static timing analysis. Compared to short combinational paths, long combinational paths are much less likely to exhibit worstcase variation at every point along the way. Synopsys primetime advanced onchip variation analysis. Time sta solution provides designers with extensive timing analysis checks, on chip variation analysis techniques, golden delay calculation, advanced modeling. During pocv sta, distribution of arrival time is assumed as gaussian and calculated by propagating and accumulating each cells variation. Synopsys primetime advanced onchip variation analysis enables renesas to accelerate timing closure at 65nm and below.
Timing, parametric analysis, on chip variation ocv. Library characterization and modelling part 2 youtube. Each one of those is expected to have a lab, where instructor will run guna as a standalone software and generate the models. In this paper we propose a new methodology, called parametric on chip variation pocv analysis, to determine local process variation effects on the timing of.
Onchip variation ocv is a recognition of the intrinsic variability of semiconductor processes and their impact on factors such as logic timing. The first task is to find all possible sources variation, and find out how these can affect a delay of a cell and hence, timing. On chip variation ocv has become a larger problem at advanced nodes 16nm and below with respect to its impact on timing. Each one of those is expected to have a lab, where instructor will run guna. Parametric on chip variation pocv cmos fundamentals.
Clock mesh technology provides uniform, low skew clock distribution and offers better tolerance to on chip variations ocv than conventional clock. So we decided to have it in 3 parts and this is part i. With billions of instances and transistors, these fpga designs require higher capacity. This course will give an eagles eye to every timing check that is being performed in current industries for signoff. The liberty technical advisory board ltab, an ieeeisto federation member program, approved extensions to cover modeling techniques such as advanced on chip. In this chapter, we study a chippackage stressaware timing coanalysis methodology for tsvbased 3d ics. The primetime sta solution provides designers with extensive timing analysis checks, onchip variation analysis techniques, golden delay calculation, advanced modeling, unmatched. Statistical sta ssta emerged in the early 2000s, providing a promising approach to address ocv. More accurate static timing analysis at advanced nodes. On chip variation is one of the most important factors that necessitate pessimism introduction in timing analysis.
And onchip variation ocv is one of them, specifically for static timing analysis. This affects timing, where the timing delay variation as a function of voltage is changing with each node. Primetime advanced ocv analysis is an efficient, easytoadopt solution that. The timing software figures out what race number the id corresponds to and adds a timestamp for that race number. Nominal delays of the logic gates as per characterization are calculated. A parametric approach for handling local variation effects in timing. A method for timing analysis of a circuit design includes, for each group of one or more instances of a cell of a cell library in the circuit design, determining timing related data for the group. Vsd library characterization and modelling part 2 vlsi. The intel quartus prime timing analyzer is a powerful asicstyle timing analysis tool that validates the timing performance of all logic in your design using an industrystandard constraint, analysis, and reporting methodology. Rfid chip timing systems accomplish this in a very elegant way. The pocv method has been implemented in a timing analysis software, and tested on. Addressing process variation and reducing timing pessimism at.
That analysis typically includes no mismatch in gate or interconnect performance at any corner. Synopsys digital and custom design platforms certified on. Onchip variation ocv static timing analysis of a design is performed to estimate its working frequency after the design has been fabricated. Synopsys primetime static timing analysis tool provides a single, golden, trusted signoff solution for timing, signal integrity, power and variationaware analysis. The timing analyzer verifies that required timing relationships are met for your design to correctly function, and confirms actual signal arrival times against the constraints that you specify. Onchip variations the sta takeaway static timing analysis of a design is performed to estimate its working frequency after the design has been fabricated. Statistical static timing analysis some ondie variation is completely random and not correlated to any spatial positioning. Accurate thermal analysis of chippackage systems ee times. Chip timing revolutionized marathon timing, but its drawbacks were recognized as well. Synopsys improves signoff accuracy for advanced soc designs.