1. Approaches to design entry Paolo PRINETTO Politecnico di Torino (Italy) University of Illinois at Chicago, IL (USA) Paolo.Prinetto@polito.it Prinetto@uic.edu www.testgroup.polito.it Lecture 2.4

2. 2 2.4 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.

3. 3 2.4 Homework  No particular homework is foreseen

4. 4 2.4 Prerequisites  Lecture # 2.3

5. 5 2.4 Further readings  No particular suggestion

6. 6 2.4 Design entry Design Entry (or Design Capture) is the set of steps to go through to enter a design description into an EDA system. Design entry

7. 7 2.4 CompilerCompiler DescriptionDescription Description translation Libraries Design Data Base

8. 8 2.4 Design entry Approaches

9. 9 2.4 Design entry Approaches Textual

10. 10 2.4 Design entry Approaches GraphicTextual

11. 11 2.4 Design entry Approaches Graphic Based on ad-hoc graphical languages Textual

12. 12 2.4 Classification behavior structure physical system RT logic device Abstraction levels Representation domains

13. 13 2.4 Classification behavior structure physical system RT logic device Abstraction levels Representation domains High Level Graphical Languages

14. 14 2.4 High Level Graphical Languages Last 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  …

15. 15 2.4 Example: Statemate SYSTEM OFF WAIT_CMD A B ON EXECUTING Y Z READ_DATAPROCESS_DATA RESET EXECUTE POWER_OFFPOWER_ON

16. 16 2.4 Classification behavior structure physical system RT logic device Abstraction levels Representation domains

17. 17 2.4 Classification behavior structure physical system RT logic device Abstraction levels Representation domains Schematic editors

18. 18 2.4 Schematic Editors They represent the “traditional” tools to represent system structure in terms of blocks and modules interconnections.

19. 19 2.4 Example

20. 20 2.4 Example of hierarchy

21. 21 2.4 Example of hierarchy

22. 22 2.4 Example of hierarchy

23. 23 2.4 Pro’s & Con’s  Easily to use  Low productivity  Applicability restricted to the structural domain, only.

24. 24 2.4 Status  In 1991, the 85% of industrial designs was based on schematics  Today, most industrial designs are based on  VHDL  Verilog  C++  Java ...

25. 25 2.4 Classification Representation domains behavior structure physical system RT logic device Abstraction levels

26. 26 2.4 Classification Representation domains behavior structure physical system RT logic device Abstraction levels Layout tools

27. 27 2.4 Layout tools  Used today mostly to develop cells libraries  Basis elements are usually represented symbolically (symbolic layout tool).

28. 28 2.4 Example [P.L. Civera]

29. 29 2.4 Design entry Approaches GraphicTextual

30. 30 2.4 Design entry Approaches GraphicTextual Based on ad-hoc programming languages, particularly tailored to the descriptions of digital systems: (Hardware Description Languages HDL) (Hardware Description Languages or HDL)

31. 31 2.4 Problems in Hardware description  Hierarchy  Concurrency  Communications among modules  Timing  Propagation delays  Different domains and abstraction levels  Technology peculiarities  Constraints descriptions  …

32. 32 2.4 Application areas behavior structure physical system RT logic device Abstraction levels Representation domains

33. 33 2.4 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 editors.