1 PAR Presentation DASC meeting at DAC, June 21, 2001 Project title: A standard for an Advanced Library Format (ALF) describing Integrated Circuit (IC) technology, cells, and blocks Official reporter: Wolfgang Roethig

2 Contributors The following people have contributed to create and review the PAR for the ALF project Jay AbrahamSilicon Metrics Tim BurksMagma Liz ChambersTera Systems Shir-Shen ChangSynopsys Joe DanielsAccellera Greg DuFourMentor Graphics Tim Ehrler Philips Simon FavreMonterey Pierre GirouardLogicVision Nancy NettletonSUN Microsystems Cynthia ParrishAdaptive Silicon Steffen RochelSimplex Wolfgang RoethigNEC Sergei SokolovSequence Li Pen YuanAvant! Corporation Alex ZamfirescuASC

3 Pertinent information (field of PAR form) New standard –Not update of existing PAR Life cycle: full use (5 years) Individual Sponsor Balloting –Expected date of initial ballot: May 2002 Projected completion date: May 2003

4 Scope (field 9 of PAR form) ALF shall serve as the primary data specification of library elements for design applications used to implement integrated circuits. The range of abstraction shall include from the register-transfer level (RTL) to the tape-out level. The language shall model behavior, timing, power, signal integrity, physical abstraction and physical implementation rules of library elements.

5 Purpose (field 10 of PAR form) The purpose of ALF is to provide a modeling language and semantics for functional, physical and electrical performance description of technology- specific libraries for cell-based and block-based design.

6 Purpose (continued) Without a standard, design implementation tools would use multiple proprietary and tool-specific library descriptions. The semantics would be defined by tool implementations only, which are subject to change and prone to mis-interpretation. Also there would be redundancy using multiple descriptions for similar library aspects. Therefore a standard is proposed to create a consistent library view suitable as a reference for all design implementation applications.

7 Pertinent information (field of PAR form) Patent policy has been reviewed with Paul Menchini Copyright of Accellera ALF specification document is being released to IEEE –contact Dennis Brophy, Accellera chairman, for details

8 Standards with similar scope (field 12 of PAR form) IEEE Std contains a clause for Procedural Interface (PI) and another clause for Delay Calculation Language (DCL). The PI defined by IEEE Std may be extended by OLA (Open Library Architecture) in the future. ALF is a standard for modeling, whereas IEEE Std and OLA are standards for data access.

9 Standards with similar scope (continued) There are standards and projects covering parts of the scope, but none of them encompassing the entire scope. Certain projects, owned by EDA vendors, are positioned and used as de-facto standards. However, their usage is not royalty-free, and versions are controlled by the vendors. Therefore, they are difficult to support, combine and enhance by parties others than the originating vendors. Furthermore, such projects do not supply languages with well-defined semantics. The semantics are given as reference implementations of particular EDA tools and are subject to change. ALF is the only proposed standard with clearly defined, unified semantics covering the entire scope of EDA applications ranging between RTL and tape-out.

10 Conclusion The ALF study group has prepared a draft PAR Signature page has been sent to Paul Menchini The ALF study group requests that the PAR be considered for approval by the DASC

11 Backup slides for discussion Not included in the PAR

12 Big picture for ALF Unified ALF library Timing Power Signal integrity Electrical model Simulation Formal verificationDesign for test Synthesis Functional model LayoutInterconnect Hierarchical design Physical model

13 Detailed picture for ALF

14 Motivation for ALF VDSM technology enables larger designs and requires knowledge of more physical and electrical details –more abstract models required –models must capture pertinent electrical and physical data –models must be efficient for design and analysis As design tools and flows become more complex, preparation of technology libraries becomes more expensive –Multiple library representations for increasing number of tools –Tool-specific libraries change versions frequently

15 Motivation for ALF (continued) Advantages of a standard library model description –reduce the cost and increase the quality of the library –less time and resources required for creation and validation –facilitate tool interoperability –leverage 3rd party library sources –enable design tools to keep pace with evolving technology spec

16 Motivation for ALF (continued) Design tools do not work in isolation any more –logical design tools are aware of layout (“physical synthesis”) –layout tools are aware of electrical constraints (timing, power, crosstalk, voltage drop) –Performance optimization tools must respect reliability and manufacturability constraints (electromigration, antenna) –DFT tools not only for functional correctness, but also electrical correctness (delay faults, severe voltage drop) As a consequence, a comprehensive and coherent modeling approach is required