嵌入式系统词汇表 A ASIC（专用集成电路） Application-Specific Integrated Circuit. A piece of custom-designed hardware in a chip. 专用集成电路。一个在一个芯片上定制设计的硬件。 address bus （地址总线） A set of electrical lines connected to the processor and all of the peripher als withwhich itcommunicates. The address bus is used by the processor to se lect aspecific memory location or register within a particular peripheral. I f the address bus contains n electrical lines, the processor can uniquely ad dress up to 2^n such locations. 一个连接处理器与所有外设的，用来通讯的电子线路集。地址总线被处理器用来选择在 特定外设中的存储器地址或寄存器。如果地址总线有n条电子线路，处理器能唯一寻址高 达2^n的地址空间。 application software（应用软件） Describes software modules specific to a particular embedded project. Theapp lication software is unlikely to be reusable across embedded platforms, simp lybecause each embedded system has a different application. 用来描述一个特定的嵌入式项目中的某一软件模块。应用软件不象可重用的交叉嵌入式 平台，只是因为每一个嵌入式系统有不同的应用软件。 assembler（汇编编译器） A software development tool that translates human-readable assembly language programs into machine-language instructions that the processor can understan dand execute. 一个能把人可读的汇编语言程序转换到处理器可理解和运行的机器指令的软件开发工具 。 assembly language（汇编语言） A human-readable form of a processor"s instruction set. Most processor-speci fic functions must be written in assembly language. 一种人可读的处理器指令集的形式。大多数处理器相关的功能必须用汇编语言编写。 B BSP（板卡支持包） See board support package. 见board support package。 binary semaphore(二元信号) A type of semaphore with just two states. Also called a mutex. 一种只有两种状态的信号。也叫互斥信号。 board support package（板卡支持包） Part of a software package that is processor or platform-dependent. Typicall y,sample source code for the board support package is provided by the packag e developer. The sample code must be modified as necessary, compiled, and li nked with the remainder of the software package. 软件包的具有平台依赖性的那一部分。典型地，板卡支持包的样例源程序由包开发者提 供。样例源程序必须能在需要时被修改、编译并与软件包的剩下的部分连接起来。 bond-out processor （外合处理器） A special version of a processor that has some of the internal signals broug ht out to external pins. A bond-out processor is most often found within an emulator and is never intended to be used in a production system. 一种特殊版本的处理器，它有一些，内部的信号能传达到外置的针脚上。一个外合处 理器绝大多数情况下只用在模拟器上，从来不会被特意用在产品系统上。 Breakpoint （断点） A location in a program at which execution is to be stopped and control of t he processor switched to the debugger. Mechanisms for creating and removing breakpoints are provided by most debugging tools. 一个在程序中的地址，在那里程序的执行被停止，并且处理器的控制转换到了除错程 序。大多数除错工具提供增加与删除一个断点的机制。 C CISC（复杂指令集计算机） Complex Instruction Set Computer. Describes the architecture of a processor family. CISC processors generally feature variable-length instructions, mult iple addressing formats, and contain only a small number of general-purpose registers. Intel"s 80x86 family is the quintessential example of CISC. Contr ast with RISC. 复杂指令集计算机。对一种处理器架构的描述。CISC处理器一般产生变长的指令，多 种地址格式，并且仅仅有少量的通用寄存器。Intel的80x86家族是是典型的CISC处理器 。相对于RISC而言。 CPU（中央处理器） Central Processing Unit. The part of a processor that executes instructions. 中央处理器。处理器中执行指令的那一部分。 Compiler（编译器） A software development tool that translates high-level language programs int o the machine-language instructions that a particular processor can understa nd and execute. 把高级编程语言程序转换到只有特定的处理器能了解和执行的机器指令的一种软件开发 包。 context （上下文） The current state of the processor"s registers and flags. 处理器当前的状态和标志。 context switch（上下文切换） The process of switching from one task to another in a multitasking operatin g system. A context switch involves saving the context of the running task a nd restoring the previously-saved context of the other. The piece of code th at does this is necessarily processor-specific. 在多任务操作系统中我一个任务切换到另一个的过程。上下文切换包括保存正在运行的 任务的上下文和恢复早先保存的另一个任务的上下文。做这个工作的一段代码必须具有 处理器特权。 counting semaphore（计数信号） A type of semaphore that is used to track multiple resources of the same typ e. An attempt to take a counting semaphore is blocked only if all of the ava ilable resou