IWSFT2005 <Formal Method> 12005/11/08 - 10

A Layered Formal Specification of Contactless IC Card "FeliCa"Kyushu University (JAPAN)

Xiaojing ZHANG, Yoichi OMORI and Keijiro ARAKI

BackgroundConsumer embedded

systems Product family development Short interval between releases Similar service with variable platform

Software productline Extracts commonalities of a series of products Manage and improve core asset

Application Engineering<Reuse>

Domain Engineering<Extract>

Management<Feedback>

Core Asset

IWSFT2005 <Formal Method> 22005/11/08 - 10

Feedback process from product to core asset is complicate

Product is complicatedly mixed Which part should we feedback to the core asset?

Formal specifications help clarifying commonalities and differences

PurposePropose a layered architecture of specification

To improve efficiency of the feedback process

ApproachSeparate descriptions between logical and

physical level by hardware dependencyApply to Contactless IC card "FeliCa“

IWSFT2005 <Formal Method> 32005/11/08 - 10

Core AssetSoftwareProduct feedback

specification innatural language Physical Layer

(variable components)

Logical Layer(common components)

＋

reuse

Layered Architecture

Figure1: Concept Of Research

separation

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Method Layered architecture

Logical layer preserved data with logical meaning Operations derived from design purpose

Physical layer Physical structure of data Algorithms or procedure of operations

1. Divide natural language specification into several modules

2. separate each module into Logical Layer and Physical Layer by principles above

3. Draw class diagrams in UML, and then materialize them to VDM++

4. Inheritance are used temporarily Gathering only physical descriptions can’t make the layer complete To make up shortage; To indicate correspondency

IWSFT2005 <Formal Method> 52005/11/08 - 10

Case Study: FeliCa CardDivide card into file system and commands

File System – data structure on card memory Data hold on the memory area Operations access the data Type of the data Operations about types

Commands – protocol between card and R/W Command/Response packet Command purpose Structure of packet Procedure of command’s operation

Future Works Improve and formalize the method

How to express both independency and correspondency?

Logical Layer Class

Physical Layer Class

Logical Layer Class

Physical Layer Class

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Class ofLogical Layer

File System

inheritance

Figure2: Class Diagram Of Commands (partial)

Class ofPhysical Layer

Module: Command Polling