从行为映射到结构 USTC Transport Decode Implemented Behavior vs.Architecture as Software Task Running what does it do?vs.How it is constructed on Microcontroller Communication External DSP Over Bus Processor 12 lo Synch onrol MPEG SP RAM Rate Video Frame Video Front Ead 1 Decode 6 Outpat 8 Peripheral Control Processor Audio Derode Audio Decode System RAM 11 GPPs SPPs Audio Decode Behavior Implemented on Dedicated Hardware
从行为映射到结构 Behavior vs. Architecture what does it do? vs. How it is constructed llxx@ustc.edu.cn 11/71 GPPs + SPPs
系统的复杂性和异构性 controller control panel processes Real-time ASIC U川 ucontroller OS processes DSP Programmable Programmable DSP Assembly DSP DSP Assembly Code Code Dual-ported CODEC RAM 。 异构性表现在硬件和软件两方面 -SW(粉)：control oriented,DSP oriented -HW(青)：ASICs,COTS ICs llxx@ustc.edu.cn 12/71
系统的复杂性和异构性 controller control panel Real-time OS controller processes UI processes ASIC Programmable Programmable DSP DSP llxx@ustc.edu.cn 12/71 • 异构性表现在硬件和软件两方面 – SW（粉）: control oriented, DSP oriented – HW（青）: ASICs, COTS ICs Programmable DSP Programmable DSP DSP Assembly Code DSP Assembly Code Dual-ported RAM CODEC
传统的嵌入式系统设计模型 USTC HWCI HW Development Testing Fabric. Detailed Prelim. Design Hardware Design Sys/HW Require. Require. Analysis Analysis System System Operation. Concepts Integ.and Testing and Sys/SW test Eval. Require. Analysis Software Require. Analysis Prelim. Design Detailed Design Coding, Unit test., SW Development Integ.tes CSCI Testing 13/71
传统的嵌入式系统设计模型 Sys/HW HWCI Testing Hardware Require. Analysis Prelim. Design Detailed Design Fabric. HW Development 13/71 System Concepts Sys/HW Require. Analysis Sys/SW Require. Analysis Operation. Testing and Eval. Software Require. Analysis Prelim. Design Detailed Design Coding, Unit test., SW Development Integ. test CSCI Testing System Integ. and test Analysis
传统的嵌入式系统设计过程 ·传统软硬件设计过程的基本特征： 一系统在一开始就被划分为软件和硬件两大部分 一软件和硬件独立进行开发设计 -“Hardware first”approach often adopted 隐含的一些问题： specification 一软硬件之间的交互受到很大限制 partitioning into HW and SW 。 软硬件的相互性能影响很难评估 HW-architecture 一系统集成相对滞后，NRE较大 SW-architecture 因此： implementation -Poor quality designs(设计质量差) integration test -Costly modifications(设计修改难) - Schedule slippages(研制周期不能有效保障) llxx@ustc.edu.cn 14/71
传统的嵌入式系统设计过程 • 传统软硬件设计过程的基本特征: – 系统在一开始就被划分为软件和硬件两大部分 – 软件和硬件独立进行开发设计 – “Hardware first” approach often adopted • 隐含的一些问题: – 软硬件之间的交互受到很大限制 llxx@ustc.edu.cn 14/71 • 软硬件的相互性能影响很难评估 – 系统集成相对滞后，NRE较大 • 因此: – Poor quality designs （设计质量差） – Costly modifications （设计修改难） – Schedule slippages（研制周期不能有效保障）
软硬件协同设计模型 2 P☒ MS的作用：保证随着设计过程的进展，能不断 地进行设计确认！ HWCI HW Development Testing Fabric. Detailed Prelim. Design Hardware Design Sys/HW Require. Require. Analysis System Analysis Integrated Modeling Substrate System Operation. Concepts Integ.and Testing ang Sys/SW test Evaluation Require. Analysis Software Require. Analysis Prelim. Design Detailed Design Coding, Unit test., SW Development Integ.test CSCI Testing ©EEE1991 [Franke91]
软硬件协同设计模型 Hardware Require. HW Development HWCI Testing Prelim. Design Detailed Design Fabric. IMS的作用：保证随着设计过程的进展，能不断 地进行设计确认！ System Concepts Sys/HW Require. Analysis Sys/SW Require. Analysis Require. Analysis Software Require. Analysis Operation. Testing and Evaluation SW Development System Integ. and test CSCI Testing [Franke91] Integrated Modeling Substrate Prelim. Design Detailed Design Coding, Unit test., Integ. test © IEEE 1991