Application of UML for Hardware Design Based on Design Process Model

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Application of UML for Hardware Design Based on
Design Process Model
Authors R. Damasevicius, V. Stuikys

• Speaker Prof. Vytautas STUIKYS,
• Software Engineering Department,
• Kaunas University of Technology,
• Kaunas, Lithuania
• E-mail vystu_at_if.ktu.lt
• Phone [phone]

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Content

• Motivation
• Higher-Level Abstractions Design Processes
  UML-Based Specification
• Taxonomy, Definition, Examples
• Metamodel for Conversion of a given Specification
  from UML to VHDL
• Design Flow, Experiments
• Evaluation, Discussion, Conclusions

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MOTIVATION

• MAIN DESIGN PROBLEM (Complexity and its
  derivatives - quality, productivity, time-to
  market) can be solved through
• Higher Reuse content at all design levels
• System-Level Design
• Novel design methodologies (e.g., Platform-Based
  Design)
• Standardization initiatives
• RAISING THE ABSTRACTION LEVEL IN DESIGN
• We INTRODUCE 3 higher-level abstractions
• DESIGN PROCESSES
• UML for specifying Design Processes (PD)
• METAPROGRAMMING for specifying generic
  functionality within a DP

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Design Processes within Platform-Based Design
General View
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Object-Oriented (OO) View to HL Design Processes
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High-level (HL) and Low-level (LL) Design
Processes
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UML Class Diagrams Graphical Notation
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Object-Oriented (OO) View to HL HW Design
Processes Taxonomy

• Basic Operations
• Refinement, Widening
• Narrowing, Containment
• Logical Composition, Physical Composition
• Design Patterns (processes) as a specific
  combination of Basic Operations
• Wrapping, Specialization
• Composition, Recursive Composition

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Example 1 Refinement
VHDL
UML

• Interface class is given in italic
• Refinement (HW domain) Realization (SW domain)

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Example 2 Widening
VHDL
UML

• Widening (HW domain) Inheritance (SW domain)
• Narrowing (HW domain) inversion of Widening (HW
  domain)

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Example 4 Containment
VHDL
UML

• Containment (HW domain) Composition (SW domain)

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Example 5 Logical Composition
VHDL
UML

• Logical Composition (HW domain) Multiple
  Inheritance (SW domain)

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Example 6 Physical Composition
VHDL
UML

• Physical Composition (HW domain) Composition
  (SW domain)

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Wrapping Design Process
Block diagram
UML

• Wrapping Design Process (HW domain) ? Decorator
  Design Pattern (SW domain)

• For details, and VHDL code see
  http//soften.ktu.lt/stuik/dac03/

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Metamodel and Transformation from UML to VHDL (1)

• UML Interface VHDL Entity

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Metamodel and Transformation from UML to VHDL (2)

• UML Inheritance ? VHDL abstraction
• Inheritance (widening) is implemented using the
  metaprogramming techniques

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Metamodel and Transformation from UML to VHDL (3)

• UML Realization Refinement (VHDL
  entity-architecture)

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Metamodel and Transformation from UML to VHDL (4)

• UML Composition HW Containment (VHDL Port map)

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What Is a Design Process?

• Design Process (DP) is
• More than a simple design pattern
• A domain-specific generative process
• A pattern that includes
• documentation (well-proven models, natural
  language descriptions, UML diagrams), which
  describes a design solution,
• domain code components, and
• tools (parsers, generators, etc.), which
  implement the solution
• For properties of DPs (see paper)

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Detailed Design Flow Automatic Generation of
Instances in VHDL
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Experimental Approval

• Design Problems very close to the Real World
  Design Problems we have solved
• IP Communication Problems
• Based on HandShake Model
• Based on FIFO Communication Model
• Reliable Components (sub-systems, IPs) based on
  TRM
• Based on SPACE redundancy
• Based on DATA redundancy
• Based on TIME redundancy
• Third-party Soft IPs Freely available the
  coarse-grained components in VHDL (Free-6502
  core, DRAGONFLY core, AX8 core, i8051
  micro-controller, etc.)
• Important note All above stated design problems
  can be specified using the same PD- WRAPPER
  DESIGN PATTERN

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Evaluation of the Approach at the Design Process
Level

• HW Design Processes (DPs) reside within some
  framework such as Platform-Based Design
• HW designers conceive DPs usually intuitively (on
  previous knowledge and design experience basis)
• In our view, DP is an abstraction (model) and it
  can be treated at different levels of
  abstractions
• A HW DP not always matches to the SW DP
  (Patterns)
• Perhaps (our vision) HW DPs are richer than SW
  DPs
• The same DP can be expressed using different
  relationships

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Evaluation of the Approach at the Specification
Level

• Advantages of using UML for HW design
• Graphical, OO, standard, well-documented, serious
  efforts for applying in HW domain now, may serve
  for converging SW/HW design
• High level specification (abstraction) of a
  designed system
• Soft IP reusability, adaptability,
  maintainability for reuse
• Difficulties of using UML for HW design relate
  with
• Specification of interconnections between
  components, generic domain functionality
• Model validation, increased initial development
  time
• Relationship UML /non-OO HDL is not
  well-understood yet
• Expressiveness of UML for HW DP is not enough
• A little maturity in usage of UML for HW design
• Some problems with metamodel (UML subset/VHDL
  subset)

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General Evaluation of the Proposed Approach

• Several problems are still left to be solved
• How to select a HDL to implement the OO model of
  a system?
• SystemC (an OO HDL) is better for HW modeling,
  HW/SW co-simulation and IP reuse
• VHDL (not an OO HDL) is better for optimization
  and synthesis
• Which specification method is better for HW
  design block-based or OO?
• Block diagrams are more common for HW designers.
  They are more straightforward and are oriented at
  interconnecting components
• UML class diagrams are more intuitive and
  oriented at reusing and customizing components

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SUMMARY CONCLUSION

• We have shown that High-level Abstractions play a
  key role in System-Level Design
• We have introduced and discussed 3 types of
  Abstractions for System-Level Design
• Design Process as a higher-level (or meta) model
• UML for Specification and Implementation of the
  model
• MetaProgramming for generic Specification
  (partially)
• We have (1) introduced taxonomy of UML- based
  Design Processes at two levels Operations and
  Design Patterns, (2) discussed Design Flow based
  on MetaModel (UML-VHDL) and its implementation
  using UMLStudio Tools, and (3) evaluated the
  proposed methodology

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Application of UML for Hardware Design Based on
Design Process Model

• Thank You for Your attention !
• http//soften.ktu.lt/stuik/group/