【正文】 ? 嵌入到對象體系中的專用計算機系統(tǒng)。 ? Intel PCA架構； PXA255應用處理器 Why use microprocessors? ? Alternatives: fieldprogrammable gate arrays (FPGAs), custom logic, etc. ? Microprocessors are often very efficient: can use same logic to perform many different functions. ? Microprocessors simplify the design of families of products. The performance paradox ? Microprocessors use much more logic to implement a function than does custom logic. ? But microprocessors are often at least as fast: ? heavily pipelined。在主機上模擬了目標機中處理器的功能和指令， ? 特點 ? 簡單可行 ? 缺乏在線調試功能和實時仿真功能 ? 僅能模擬目標處理器，無法模擬處理器有關 I/O的功能 ? 常作為初步基本調試工具 ICE ? ICE: InCircuit Emulator ? 傳統(tǒng)用于測試印刷電路板的方法。因此，無法用常規(guī)的在線仿真的方式 … Embedded ICE ? Embedded ICE: 一組調試寄存器 ? IBCR (Instruction Break Control Register) ? DBAR (Data Break Address Register) ? … ? JTAG接口 ? JTAG(Joint Test Action Group) 制定了邊界掃描標準，只需 5根引腳就可以實現(xiàn)在線仿真的功能。 ? 功能 ? Debug。通過軟中斷 SWI指令來實現(xiàn)。從而能實現(xiàn)調試、通信和管理等操作的要求。 ? work to most detailed. ? Bottomup design: ? work from small ponents to big system. ? Real design uses both techniques. Stepwise refinement ? At each level of abstraction, we must: ? analyze the design to determine characteristics of the current state of the design。 ? size, weight, etc.。 thre ere so lutions 。 ? user interface。 答案要點： 結合例子，說明嵌入式系統(tǒng)的組成部分： （ 1） 硬件部分 ? a) 微處理器： ? b) 內存： ? c) I/O部分（模塊、驅動器和設備）： （ 2） 軟件部分： 開發(fā)過程 。 ? background operations needed to keep the system running. Architecture design ? What major ponents go satisfying the specification? ? Hardware ponents: ? CPUs, peripherals, etc. ? Software ponents: ? major programs and their operations. ? Must take into account functional and nonfunctional specifications. GPS moving map block diagram GPS receiver search engine renderer user interface database display GPS moving map hardware architecture GPS receiver CPU panel I/O display frame buffer memory GPS moving map software architecture position database search renderer timer user interface pixels Designing hardware and software ponents ? Must spend time architecting the system before you start coding. ? Some ponents are readymade, some can be modified from existing designs, others must be designed from scratch. System integration ? Put together the ponents. ? Many bugs appear only at this stage. ? Have a plan for integrating ponents to uncover bugs quickly, test as much functionality as early as possible. Review 試舉一個嵌入式產(chǎn)品的例子，詳細說明其需求、規(guī)格說明、體系結構和各個組成部分。 ? provides input to the architecture design process. ? May include functional and nonfunctional element