I/O space（I/O空間）

　　A special memory region provided by some processors and generally reserved for the attachment of I/O devices. Memory locations and registers within an I/O space can be accessed only via special instructions. For example, processors in the 80x86 family have special I/O space instructions called in and out. Contrast with memory space.

　　一個由處理器提供的特殊內(nèi)存區(qū)域，一般為為I/O設(shè)備的附件保留。在I/O空間的內(nèi)存位置和寄存器只能通過特殊的指定進(jìn)行訪問。例如：80X86家族的處理器有叫做in/out的特殊的I/O空間指令。相對內(nèi)存空間而言。

　　ISR（中斷服務(wù)程序）

　　See interrupt service routine.

　　instruction pointer（指令指針）

　　A register in the processor that contains the address of the next instruction to be executed. Also known as a program counter.

　　包含下一條要執(zhí)行指令地址的處理器中的寄存器。也叫程序計數(shù)器。

　　Interrupt（中斷）

　　An asynchronous electrical signal from a peripheral to the processor. When the peripheral asserts this signal, we say that an interrupt occurs. When an interrupt occurs, the current state of the processor is saved and an interrupt service routine is executed. When the interrupt service routine exits, control of the processor is returned to whatever part of the software was previously running.

　　一個從外設(shè)到處理器的異步電信號。當(dāng)外設(shè)發(fā)出這個信號，我們說一個中斷發(fā)生。當(dāng)一個中斷發(fā)生，當(dāng)前的處理器狀態(tài)被保存并且中斷服務(wù)程序開始運行。當(dāng)中斷服務(wù)程序退出，對處理器的控制權(quán)轉(zhuǎn)到先前運行的那個軟件上。

　　interrupt latency（中斷延遲）

　　The amount of time between the assertion of an interrupt and the start of the associated interrupt service routine.

　　在中斷發(fā)生和相關(guān)的中斷服務(wù)程序運行之間的時間長短。

　　interrupt service routine（中斷服務(wù)程序）

　　A piece of software executed in response to a particular interrupt.

　　響應(yīng)特定中斷而運行的一小段軟件。

　　interrupt type（中斷類型）

　　A unique number associated with each interrupt.

　　和每一個中斷相關(guān)聯(lián)的唯一數(shù)字。

　　interrupt vector （中斷向量）

　　The address of an interrupt service routine.

　　中斷服務(wù)程序所在的地址。

　　interrupt vector table（中斷向量表）

　　A table containing interrupt vectors and indexed by interrupt type. This table contains the processor's mapping between interrupts and interrupt service routines and must be initialized by the programmer.

　　一個表格，包含由中斷類型決定的中斷向量和索引。這個表格包含中斷與中斷服務(wù)程序之間的處理器的映射，必須由程序員進(jìn)行初始化。

　　intertask communication（進(jìn)程間通訊）

　　A mechanism used by tasks and interrupt service routines to share information and synchronize their access to shared resources. The most common building blocks of intertask communication are semaphores and mutexes.

　　一種被用來在任務(wù)和中斷服務(wù)程序之間共享信息和同步它們對共享資源訪問的機(jī)制。大部分進(jìn)程間通訊的建立的基石是信號燈和互斥。

K

　　Kernel（內(nèi)核）

　　An essential part of any multitasking operating system, the kernel contains just the scheduler and context-switch routine.

　　任何多任務(wù)操作系統(tǒng)的本質(zhì)部分，內(nèi)核僅僅包含調(diào)度程序和上下文切換進(jìn)程。

L

　　Linker（連接程序）

　　A software development tool that accepts one or more object files as input and outputs a relocatable program. The linker is thus run after all of the source files have been compiled or assembled.

　　一種能把一個或更多目標(biāo)文件組合成可輸入和輸出的可重定位程序的開發(fā)工具。連接程序在所有的源文件都被編譯或匯編之后運行。

　　Locator（定位程序）

　　A software development tool that assigns physical addresses to the elocatable program produced by the linker. This is the last step in the preparation of software for execution by an embedded system and the resulting file is called an executable. In some cases, the locator's function may be hidden with in the linker.

　　一種分配物理地址給連接程序處理過的可重定位程序的軟件開發(fā)工具。這是準(zhǔn)備一個軟件在嵌入式系統(tǒng)中運行的最后一步，并且結(jié)果文件叫做可執(zhí)行的。在一些情況下，定位程序功能隱藏在連接程序中。

　　logic analyzer（邏輯分析儀）

　　A hardware debugging tool that can be used to capture the logic levels(0or1) of dozens, or even hundreds, of electrical signals in real-time. Logic analyzers can be quite helpful for debugging hardware problems and complex processor-peripheral interactions.

　　一種硬件調(diào)試工具，能捕獲實時電信號的許多邏輯電平（0或1），邏輯分析儀在調(diào)試硬件問題和復(fù)雜的處理外設(shè)交互時相當(dāng)有用。

M

　　memory map（內(nèi)存映射）

　　A table or diagram containing the name and address range of each peripheral addressable by the processor within the memory space. Memory maps are a helpful aid in getting to know the target.

　　一個在內(nèi)存空間中的，包含每個外設(shè)的名字和可由處理器設(shè)置的地址范圍的表格或圖表。內(nèi)存映射有助于了解目標(biāo)機(jī)情況。

　　memory-mapped I/O（內(nèi)存映射I/O）

　　An increasingly common hardware design methodology in which I/O devices are placed into the memory space rather than the I/O space. From the processor's point of view, memory-mapped I/O devices look very much like memory devices.

　　一種日益流行的硬件設(shè)計方法，在這種方法中，I/O設(shè)備被放置在內(nèi)存空間而不是I/O空間。從處理器的觀點看，內(nèi)存映射I/O設(shè)備看上去很象內(nèi)存一樣。

　　memory space（內(nèi)存空間）

　　A processor's standard address space. Contrast with I/O space.

　　一個處理器的標(biāo)準(zhǔn)地址空間。相對I/O空間。

　　Microcontroller（微控制器）

　　A microcontroller is very similar to a microprocessor. The main difference is that a microcontroller is designed specifically for use in embedded systems Microcontrollers typically include a CPU, memory (a small amount of RAM and/or ROM), and other peripherals on the same chip. Common examples are the 8051, Intel's 80196, and Motorola's 68HCxx series.

　　微控制器很像微處理器。主要的差別在于微控制器被特殊設(shè)計用在嵌入式系統(tǒng)中。微控制器典型地包括CPU、內(nèi)存（很小的RAM或ROM），還有其他的外設(shè)，它們在同一塊芯片上。常見的例子是：8051、Intel80196、Motorola68HCxx系列。

　　Microprocessor（微處理器）

　　A piece of silicon containing a general-purpose CPU. The most common examples are Intel's 80x86 and Motorola's 680x0 families.

　　一片包含通用CPU的硅片。常見的例子是：Intel80x86、Motorola 680x0系列。

　　Monitor（監(jiān)視器）

　　In the context of this book, a debug monitor. However, there is a second meaning for this word that is associated with intertask communication. In that context, a monitor is a language-level synchronization feature.

　　在這本書的上下文中，是指調(diào)試監(jiān)視器。然而，第二個意思與任務(wù)間通訊相關(guān)聯(lián)。在那個上下文中，監(jiān)視器是高級同步機(jī)制的特性。

　　Multiprocessing（多處理）

　　The use of more than one processor in a single computer system. So called "multiprocessor systems" usually have a common memory space through which the processors can communicate and share data. In addition, some multiprocessor systems support parallel processing.

　　在單個的計算機(jī)系統(tǒng)中有多個處理器。被叫作“多處理器系統(tǒng)”的一般有公用的內(nèi)存空間，處理器通過它們進(jìn)行通訊和共享數(shù)據(jù)。另外，一些多處理器系統(tǒng)支持并行處理。

　　Multitasking （多任務(wù)）

　　The execution of multiple software routines in pseudo-parallel. Each routine represents a separate "thread of execution" and is referred to as a task. The operating system is responsible for simulating parallelism by parceling out the processor's time.

　　偽并行運行的多個軟件程序。每一個程序表現(xiàn)得像分開的“執(zhí)行的線程”并且被看作是一個任務(wù)。操作系統(tǒng)通過分配處理器時間來模擬并行方式。

　　Mutex（互斥）

　　A data structure for mutual exclusion, also known as a binary semaphore. A mutex is basically just a multitasking-aware binary flag that can be used to synchronize the activities of multiple tasks. As such, it can be used to protect critical sections of the code from interruption and shared resources from simultaneous use.

　　表現(xiàn)互斥現(xiàn)象的數(shù)據(jù)結(jié)構(gòu)，也被當(dāng)作二元信號燈。一個互斥基本上是一個多任務(wù)敏感的二元信號，它能用作同步多任務(wù)的行為，它常用作保護(hù)從中斷來的臨界段代碼并且在共享同步使用的資源。

　　mutual exclusion（互斥現(xiàn)象）

　　A guarantee of exclusive access to a shared resource. In embedded systems, the shared resource is typically a block of memory, a global variable, or a set of registers. Mutual exclusion can be achieved with the use of a semaphore or mutex.

　　唯一訪問共享資源的保證。在嵌入式系統(tǒng)中，共享的資源典型的有內(nèi)存塊或寄存器組。互斥現(xiàn)象能由使用信號燈或互斥完成。

N

　　NVRAM

　　Non-Volatile Random-Access Memory. A type of RAM that retains its data even when the system is powered down. NVRAM frequently consists of an SRAM and a　long-life battery.

　　非易失的隨機(jī)訪問存儲器。一種能在系統(tǒng)關(guān)機(jī)的情況下保持它的數(shù)據(jù)的RAM。NVRAM常常由SRAM和長壽命電池組成。

O

　　OTP

　　See one-time programmable.

　　object code（目標(biāo)代碼）

　　A set of processor-readable opcodes and data. The output of compilers, assemblers, linkers, and locators are files containing object code.

　　處理器能讀的操作碼和數(shù)據(jù)。編譯器、匯編器、連接器和定位器的輸出文件都含有目標(biāo)代碼。

　　object file（目標(biāo)文件）

　　A file containing object code. The output of a compiler or assembler.

　　包含目標(biāo)代碼的文件。編譯器或匯編器的輸出。

　　one-time programmable（一次可編程的）

　　Any programmable device, like a PROM, that can be programmed just once by the end user. However, this term is used almost exclusively to refer to micro controllers with on-chip PROM.

　　任一可編程的設(shè)備，像PROM，僅僅能被最終用戶編程一次。然而，這個術(shù)語一般被專有地使用在擁有片上PROM的微控制器上。

　　opcode

　　A sequence of bits that is recognized by the processor as one of the instructions in its instruction set.

　　一串被處理器驗證過的二進(jìn)制位的序列，它作為其指令集的一個子集。

　　operating system（操作系統(tǒng)）

　　A piece of software that makes multitasking possible. An operating system typically consists of a set of function calls, or software interrupts, and a periodic clock tick. The operating system is responsible for deciding which task should be using the processor at a given time and for controlling access to shared resources.

　　使多任務(wù)能夠?qū)崿F(xiàn)的一個軟件。一個操作系統(tǒng)典型地由一個函數(shù)調(diào)用集、軟件中斷和定期時鐘周期組成。一個操作系統(tǒng)負(fù)責(zé)決定哪一個任務(wù)在給定的時間將使用處理器，并且控制對共享資源的訪問。

　　Oscilloscope（示波器）

　　A hardware debugging tool that allows you to view the voltage on one or more electrical lines. For example, you might use an oscilloscope to determine if a particular interrupt is currently asserted.

　　一種硬件調(diào)試工具，它讓你能觀察到一個或更多電路上的電壓。例如：如果一個特殊的中斷發(fā)生，你可以用一個示波器去檢測它。

P

　　PROM（可編程只讀存儲器）

　　Programmable Read-Only Memory. A type of ROM that can be written (programmed) with a device programmer. These memory devices can be programmed only once, so they are sometimes referred to as write-once or one-time programmable devices.

　　可編程只讀存儲器。能被設(shè)備編程器寫的一種ROM。這種內(nèi)存設(shè)備可以被編程一次，所以它們有時被作為寫一次或一次性編程設(shè)備來看待。

　　parallel processing（并行進(jìn)程）

　　The ability to apply two or more processors to a single computation.

　　一種在單個計算機(jī)上運行兩個或多個程序的能力。

　　Peripheral （外設(shè)）

　　A piece of hardware other than the processor, usually memory or an I/O device. The peripheral may reside within the same chip as the processor, in which case it is called an internal peripheral.

　　一種不同于處理器的硬件設(shè)備，常指內(nèi)存或I/O設(shè)備。外設(shè)經(jīng)常和處理器在一片芯片上，在這種情況下，它被稱為集成外設(shè)。

　　physical address（物理地址）

　　The actual address that is placed on the address bus when accessing a memory location or register.

　　當(dāng)訪問內(nèi)存位置或寄存器時，在地址總線上的真實的地址。

　　Preemptive（搶先）

　　A scheduler is said to be preemptive if it allows the running task to be suspended when a higher-priority task becomes ready. Non-preemptive schedulers are easier to implement but less appropriate for embedded systems.

　　當(dāng)一個高優(yōu)先級的任務(wù)準(zhǔn)備好時，充許正在運行的任務(wù)被掛起的調(diào)度策略被稱為優(yōu)先。無優(yōu)先的調(diào)度策略更容易實現(xiàn)一些但適合在嵌入式系統(tǒng)中使用。

　　Polling(輪詢)

　　A method of interfacing with hardware that involves repeatedly reading a status register until the device has reached the awaited state. Device drivers are either polling or interrupt-driven, with the latter being more generally preferred.

　　一種硬件交互方法，不斷讀狀態(tài)寄存器，直到設(shè)備進(jìn)入等待狀態(tài)。設(shè)備驅(qū)動程序不是輪詢的就是中斷驅(qū)動的，后一種越來越成為首選的。

　　Priority（優(yōu)先）

　　The relative importance of one task compared to another.

　　一個任務(wù)與其他任務(wù)相比的重要關(guān)系。

　　priority inversion（優(yōu)先轉(zhuǎn)置）

　　An unwanted software situation in which a high-priority task is delayed while waiting for access to a shared resource that is not even being used at the time. For all practical purposes, the priority of this task has been lowered during the delay period.

　　一種不希望發(fā)生的軟件狀態(tài)，在此狀態(tài)一個高優(yōu)先級任務(wù)因為等待訪問一個那時不再使用的共享資源而被延遲。在所有的實踐目標(biāo)中，這個任務(wù)的優(yōu)先級在延遲周期內(nèi)都被降低。

　　Process（進(jìn)程）

　　A word that is often confused with task or thread. The crucial distinction is that all of the tasks in a system share a common memory space. Processes, on the other hand, always have their own private memory space. Processes are common in multi-user systems but are rarely, if ever, found in embedded systems.

　　這個名詞經(jīng)常與任務(wù)或線程混淆。至關(guān)重要的差別在于系統(tǒng)中的所有任務(wù)共享公共的內(nèi)存空間。進(jìn)程，另一方面，常常有它們自己的私有內(nèi)存空間。進(jìn)程在多用戶系統(tǒng)中，但少有地，如有可能，也可在嵌入式系統(tǒng)中。

　　Processor（處理器）

　　A generic term that does not distinction between microprocessor, microcontroller, and digital signal processor.

　　一個對于微處理器、微控制器他數(shù)字信號處器無差別的通用術(shù)語。

　　processor family（處理器族）

　　A set of related processors, usually successive generations from the same manufacturer. For example, Intel's 80x86 family began with the 8086 and now in cludes the 80186, 286, 386, 486, Pentium, and many others. The later models in a family are typically backwards-compatible with the ones that came before.

　　一個相關(guān)的處理器集，常常連續(xù)地從一個生產(chǎn)商產(chǎn)生。例如：Intel's 80x86族開始從8086開始，現(xiàn)在有80186, 286, 386, 486, Pentium及其他。在一個族中，稍后的產(chǎn)品典型地向后兼容在它以前生產(chǎn)的產(chǎn)品。

　　processor-independent（處理器無關(guān)）

　　A piece of software that is independent of the processor on which it will be run. Most programs that can be written in a high-level language are processor-independent. Contrast with processor-specific.

　　一個與處理器無關(guān)的，并能在其上運行的軟件。大多數(shù)用高級語言編寫程序是處理器無關(guān)的。相對于處理器定制。

　　processor-specific（處理器定制）

　　A piece of software that is highly dependent on the processor on which it will be run. Such code must usually be written in assembly language. Contrast with processor-independent.

　　一個高度依賴處理器的軟件，在上其才能運行。一些代碼必須用匯編語言編寫。相對于處理器無關(guān)