© P.Prinetto - all rights reserved Version 1.1 2.4.12.4 – Approaches to design entryECE 465Approaches to design entryPaolo PRINETTOPolitecnico di Torino (Italy)University of Illinois at Chicago, IL (USA)[email protected]@uic.eduwww.testgroup.polito.itLecture 2.422.4 Goal• This lecture introduces the approaches used, during the overall design cycle, to capture the information items related to the design itself, in an Electronic Design Automation (EDA) system.32.4 Homework• No particular homework is foreseen42.4 Prerequisites• Lecture # 2.352.4 Further readings• No particular suggestion62.4 Design entryDesign Entry (or Design Capture) is the set of steps to go through to enter a design description into an EDA system.Designentry© P.Prinetto - all rights reserved Version 1.1 2.4.22.4 – Approaches to design entryECE 46572.4 CompilerDescriptionDescription translationLibrariesDesignData Base82.4 DesignentryApproaches92.4 DesignentryApproachesTextual102.4 DesignentryApproachesGraphicTextual112.4 DesignentryApproachesGraphicBased on ad-hocgraphical languagesTextual122.4 Classificationbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdomains© P.Prinetto - all rights reserved Version 1.1 2.4.32.4 – Approaches to design entryECE 465132.4 Classificationbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdomainsHigh LevelGraphicalLanguages142.4 High LevelGraphical LanguagesLast generation languages that allow the designer to describe the system structure and/or behavior in terms of:• concurrent processes• state transition diagrams• flow-charts• blocks interconnections • …behavior structure physicalsyst emRTlogicdeviceAbstractionlevelsRepresentationdomainsHigh LevelHigh LevelGr aphicalGraphicalLanguagesLanguagesbehavior structure physicalsyst emRTlogicdeviceAbstractionlevelsRepresentationdomainsHigh LevelHigh LevelGr aphicalGraphicalLanguagesLanguages152.4 Example: StatemateSYSTEMOFFWAIT_CMDABONEXECUTINGYZREAD_DATA PROCESS_DATARESETEXECUTEPOWER_OFFPOWER_ONbehavior structure physicalsyst emRTlogicdeviceAbstractionlevelsRepresentationdomainsHigh LevelHigh LevelGr aphicalGraphicalLanguagesLanguagesbehavior structure physicalsyst emRTlogicdeviceAbstractionlevelsRepresentationdomainsHigh LevelHigh LevelGr aphicalGraphicalLanguagesLanguages162.4 Classificationbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdomains172.4 Classificationbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdomainsSchematic editors182.4 Schematic EditorsThey represent the “traditional” tools to represent system structure in terms of blocks and modules interconnections.behavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditorsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditors© P.Prinetto - all rights reserved Version 1.1 2.4.42.4 – Approaches to design entryECE 465192.4 Examplebehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditorsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditors202.4 Example of hierarchy212.4 Example of hierarchy222.4 Example of hierarchy232.4 Pro’s & Con’s+ Easily to use− Low productivity− Applicability restricted to the structural domain, only.behavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditorsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditors242.4 Status• In 1991, the 85% of industrial designs was based on schematics• Today, most industrial designs are based on− VHDL− Verilog− C++− Java− ...behavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditorsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdom ainsSchematic Schematic editorseditors© P.Prinetto - all rights reserved Version 1.1 2.4.52.4 – Approaches to design entryECE 465252.4 ClassificationRepresentationdomainsbehavior structure physicalsystemRTlogicdeviceAbstractionlevels262.4 ClassificationRepresentationdomainsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsLayouttools272.4 Layout tools• Used today mostly to develop cells libraries• Basis elements are usually represented symbolically (symbolic layout tool).behavior structure physicalsystemRTlogicdeviceAbstractionlevelsLayoutLayouttoolstoolsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsLayoutLayouttoolstools282.4 ExampleIN OUT+V +VGND GNDMNMP[P.L. Civera]behavior structure physicalsystemRTlogicdeviceAbstractionlevelsLayoutLayouttoolstoolsbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsLayoutLayouttoolstools292.4 DesignentryApproachesGraphicTextual302.4 DesignentryApproachesGraphicTextualBased on ad-hocprogramming languages, particularly tailored to the descriptions of digital systems:(Hardware Description Languages or HDL)© P.Prinetto - all rights reserved Version 1.1 2.4.62.4 – Approaches to design entryECE 465312.4 Problems in Hardware description• Hierarchy• Concurrency• Communications among modules• Timing • Propagation delays• Different domains and abstraction levels• Technology peculiarities• Constraints descriptions• …322.4 Application areasbehavior structure physicalsystemRTlogicdeviceAbstractionlevelsRepresentationdomains332.4 Pro’s & Con’s+ Allow mixed-level (system, RT, logic, device) and mixed-domain (behavior, structure, physical) descriptions+ Feed EDA & Synthesis tools+ Allow a “natural” design documentation+ Standards exist (e.g., VHDL, Verilog)+ Dramatically improve productivity− Are usually harder to learn than schematic