在設計嵌入式系統的過程中，繪圖是一種表達設計不同面向時不可或缺的方法。除了電腦輔助設計工具最常支援的電路圖之外，用來表達高階需求與結構的方塊圖也同等重要，但至今卻仍少有正規的定義，更幾乎沒有被視為用來與低階概念整合的一種形式。目前跨層之間的關係全部靠設計師手工詮釋，容易導致設計出錯。

雖然方塊圖並未被認為是必要的設計模式，我們仍主張跨層方塊圖可用於捕捉跨領域合作專案間的溝通資訊，亦即將應用層的需求轉述為技術規格，以支援後續設計空間探索之最佳化。我們提出的方法論，不僅能表達傳統封裝式的階層概念，更能夠搭配不同程度的抽象化，支援從高階概念層到實作電路層的同步化設計。我們實作一套具有上述功能的疊構式方塊圖編輯器，並定義了該編輯器的資料結構與基本操作，同時能搭配電腦輔助設計工具，支援如元件自動挑選與介面合成的相關演算法。

Diagramming is an essential part of capturing the various representations of an embedded system under design. In addition to schematics, which are the most common form supported by computer-aided design tools, block diagrams that express higher-level requirements or structures are equally important but unfortunately rarely formalized and almost never an integrated representation that is connected to those at the lower level. The reliance on manual interpretation across levels makes it error-prone.

While not mandatory, we contend that block diagrams at different levels can capture important information for facilitating communication of requirements between application experts and system designers and are crucial to design-space exploration. To support this methodology, we formalize a diagramming convention such that it can capture designs not only hierarchically but also at mixed levels of abstraction, from the highest conceptual level down to the most detailed schematic ready for layout. We demonstrate the concepts with an implementation of such a multi-level diagram editor and define the primitives and data structures for not only diagram capture but also integration with computer-aided design refinement tools including component selection and interface synthesis.

Abstract
Table of contents
Acknowledgments

1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Background and Related Work 6
2.1 Drawing Conventions for Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Drawing Intentions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.2 Diagram Layout Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.3 Diagram Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Diagram-Only Tools vs. Domain-Specific Diagramming Tools . . . . . . . . . . . . 9
2.2.1 Drawing-only Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.2 Type-Specific Diagramming Tools . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.3 Domain-Specific Diagramming Tools . . . . . . . . . . . . . . . . . . . . . 12
2.3 Feature-based Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Methodology 15
3.1 Editor Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Feature-Based Component Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2.1 Feature concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.3 Generalized Diagram in Level of Abstraction . . . . . . . . . . . . . . . . . . . . . 20
4 System Overview 21
4.1 System Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.1.1 Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.1.2 User Preference Capturing . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.2 Core Concepts of diagram editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2.1 The Editor and The Services . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2.2 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2.3 Primitive operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5 Technical Approach and Implementation 29
5.1 ViewModel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.1.1 SysLevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.1.2 Primitive Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2 Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.2.1 SysBlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.2.2 SysComponent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.2.3 SysConnector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.3 Relationship Between Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.3.1 Feature Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.3.2 Port Mapping and Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.4 Auto-complete Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6 Case study and Evaluation 45
6.1 Design Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.1.1 Diagrams of EcoMini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.1.2 Component Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.2 The Comparison with Other Diagramming Tools . . . . . . . . . . . . . . . . . . . 50
7 Conclusions and Future Work 54
7.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Acronyms 59

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