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FAQ

EMX FAQ

  1. Why do I need EMX?
  2. How accurate is EMX?
  3. Why is EMX so fast?
  4. Is EMX easy to use?
  5. Modern IC layout is really complicated with via-arrays, metal fill, and slotting rules. Do I need to massage the layout for EMX to simulate it?
  6. MOM "finger" capacitors have become critical for nanometer design. Can EMX handle them?
  7. What is Integrand's relationship with foundries?
  8. In advanced processes foundries are providing width/spacing dependent information of interconnect metals. Can EMX make use of this information?
  9. Can EMX handle thru-wafer vias?
  10. How can I get a demo license for EMX?
  11. Does Integrand do consulting on design?
  12. Does Integrand develop custom component libraries?
  13. Is EMX integrated into Cadence Virtuoso?
  14. Can EMX take advantage of multiple CPU cores?
  1. Why do I need EMX?
    EMX is an advanced EM simulator that is very fast and accurate. It is used by our customers for a variety of tasks, from designing simple structures like spiral inductors to extracting large IC layouts including inductors, capacitors, resistors and interconnect. In modern RF IC design, coupling between components and interconnect is a major source of design problems and silicon re-spins. EMX allows you to analyze large RF blocks as a whole instead of splitting the problem into smaller problems. EMX can simulate blocks with 10s of ports and up to a million mesh elements. Other competing simulation tools based on finite-element methods and boundary element methods simply cannot handle the size of problems that EMX can routinely solve. Over the last few years, EMX has become a key tool in the design flow of a number of prominent IC design houses and foundries.
  2. How accurate is EMX?
    EMX is very accurate for IC-style layouts. This is partly because you can create extremely fine meshes in EMX that accurately captures fine features of the geometry. In addition, all relevant physical effects are included in EMX: fully 3D conductors and vias with volumetric currents, accurate handling of sidewall capacitances and inclusion of all substrate effects. Using advanced numerical techniques, problems that plague other simulation tools such as low-frequency ill-conditioning have been eliminated from EMX. It is a testament to our accuracy that the the world's leading foundries, TSMC, UMC, IBM and GLOBALFOUNDRIES have all adopted EMX to develop the scalable component models for distribution in their foundry and process design kits.
  3. Why is EMX so fast?
    EMX is based on the fast multipole method. It can solve problems in linear time and memory as a function of mesh size (i.e., double the size of the problem, double the time). In addition, we have various patent-pending techniques that further speed up the simulation significantly using the structure of the underlying matrix. See the CICC 2010 paper or DAC 2004 papers that describe some of these techniques. Since EMX is so fast, IDM customers use EMX differently at different stages of the design process. Initially, EMX is used for simulating a large number of simple components like inductors to rapidly search the design space for the desired components. Then the circuit is assembled with a large number of internal ports where tuning elements such as capacitors can be connected. EMX is then used to simulate these RF circuits with 10s of internal ports. Using the results of the multiport simulation, tuning components are attached and the whole design is re-simulated for final verification and possible re-optimization. Design cycles for complex RF blocks can be reduced from several weeks to down to about a day using this approach.
  4. Is EMX easy to use?
    Most competing EM simulators are very difficult to use. They are loaded with bells and whistles and fancy GUIs which tend to make them difficult to use and learn. You typically need to take courses to learn how to use the simulator and become an "expert". We take an opposing minimalist philosophy. We have developed a very simple and clean interface to the tool which provides the user with very few options to control. Typical users are up and running with complicated examples in a matter of hours. Most of our users are RF designers and not EM simulation tool experts. In addition our interface to Cadence has been made very easy to install and use.
  5. Modern IC layout is really complicated with via-arrays, metal fill, and slotting rules. Do I need to massage the layout for EMX to simulate it?
    No. EMX automatically handles the complications of IC layout. There is no need to massage and edit the layout in order to simulate it. In fact, the same layout that goes to mask goes to the simulator.
  6. MOM "finger" capacitors are critical for nanometer design. Can EMX handle them?
    In recent years, with submicron technologies the capacitor density of "finger capacitors" or interdigitated MOM capacitors has exceeded that of the traditional thin-film MIM capacitors. In addition, MOM capacitors have very good mismatch properties and are being used for technology nodes below 0.13um. MOM capacitors lead to extremely dense meshes which cause other EM simulators to fail. EMX can do broadband frequency sweeps of MOM capacitors up to 10pF. Our customers use EMX to simulate full VCOs which include simulating MOM capacitors and inductors in the same layout.
  7. What is Integrand's relationship with foundries?
    Integrand has developed a close relationship with several of the world's major foundries. At the heart of accurate simulation is access to accurate foundry data. Integrand has made special efforts to develop parsers that use the foundry process information and convert them to EMX's process file format.
    TSMC, UMC and IBM have all licensed EMX for developing models of passives for their design kits. Integrand has ongoing research projects with the foundries so as to keep up-to-date on the latest developments and to help enable our mutual customers.
  8. In advanced processes, foundries are providing width/spacing dependent information of interconnect metals. Can EMX make use of this information?
    Yes. For example, TSMC has developed the iRCX format which contains process information that includes metal width and bias information. EMX supports and encourages our customers to use the iRCX format process file directly from TSMC.
  9. Can EMX handle thru-wafer vias?
    Yes. Integrand handles IBM's 5PAE process that has thru-wafer vias.
  10. How can I get a demo license for EMX?
    Call or send an e-mail to us. We can learn about your needs and let you know if EMX will solve your particular problems. We have attractive and cost effective business models in place for new customers that enable a smooth transition from your current design flow to one using EMX.
  11. Does Integrand do consulting on design?
    Integrand does do some consulting on design for custom structures. For example, we have designed a number of transformers and baluns for customers who do not have the bandwidth or expertise in-house to accomplish such tasks.
  12. Does Integrand develop custom component libraries?
    Yes. Occasionally we have customers who need components that are not part of the foundry design kit. We have developed custom components (such as high Q stacked inductors) and associated synthesis kits that meet the needs that the foundry cannot.
  13. Is EMX integrated into Cadence Virtuoso?
    Yes. EMX has a seamless interface into Cadence Virtuoso 5.1 and 6.1. EMX can be used to run EM simulations directly from within Virtuoso. This may involve EM simulations, generation of Spectre models, creation of symbol and schematic views, etc. EMX is intented to be run by a cirucit designer and not an EM expert. In addition, EMX can be directly linked to foundry design kits. For example, see the interface within the TSMC RDK 2.0.
  14. Can EMX take advantage of multiple CPU Cores?
    Yes. EMX is multi-threaded and can take advantage of multiple CPUs. There is a significant speed up in simulation which can be up to 10X over a single CPU run. For more details please see this paper for multi-threading statistics for a benchmark study for various examples. Separate licensing may be needed for running EMX in a multithreaded mode.