【正文】 486, Pentium及其他。在一個(gè)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。 processorindependent（處理器無(wú)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 highlevel language are processorindependent. Contrast with processorspecific. 一個(gè)與處理器無(wú)關(guān)的，并能在其上運(yùn)行的軟件。大多數(shù)用高級(jí)語(yǔ)言編寫程序是處理器無(wú)關(guān)的。相對(duì)于處理器定制。 processorspecific（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 processorindependent. 一個(gè)高度依賴處理器的軟件，在上其才能運(yùn)行。一些代碼必須用匯編語(yǔ)言編寫。相對(duì)于處理器無(wú)關(guān)。 Profiler（明細(xì)觀察程序） A software development tool that collects and reports execution statistics for your programs. These statistics include the number of calls to each subroutine and the total amount of time spent within each. This data can be used to learn which subroutines are the most critical and, therefore, demand the greatest code efficiency. 一種報(bào)告你的程序運(yùn)行統(tǒng)計(jì)數(shù)據(jù)的軟件調(diào)試工具。這些統(tǒng)計(jì)數(shù)據(jù)包括調(diào)用每個(gè)子程序的次數(shù)和用去的時(shí)間。這些數(shù)據(jù)常被用來(lái)了解哪些子程序是最關(guān)鍵的，并且，由此要求使最好的代碼有效率。 program counter See instruction pointer. R RAM（隨機(jī)訪問(wèn)存儲(chǔ)器） RandomAccess Memory. A broad classification of memory devices that includes all devices in which individual memory locations may be read or written as required. 隨機(jī)訪問(wèn)存儲(chǔ)器。一個(gè)包含了所有每個(gè)地址能被按需讀寫的存儲(chǔ)設(shè)備的粗略分類。 RISC（精簡(jiǎn)指令集計(jì)算機(jī)） Reduced Instruction Set Computer. Describes the architecture of a processor family. RISC processors generally feature fixedlength instructions, a loadstore memory architecture, and a large number of generalpurpose registers and/or register windows. The MIPS processor family is an excellent example. Contrast with CISC. 精簡(jiǎn)指令集計(jì)算機(jī)。一個(gè)處理器族的描述。RISC處理器一般的特征是固定長(zhǎng)度的指令集，一個(gè)負(fù)載儲(chǔ)備存儲(chǔ)結(jié)構(gòu)，和大量通用寄存器，及寄存器窗口。MIPS處理器族是極好的例子。相對(duì)CISC而言。 ROM（只讀存儲(chǔ)器） ReadOnly Memory. A broad classification of memory devices that includes all devices in which the individual memory locations may be read, but not written. 只讀存儲(chǔ)器。一個(gè)包括所的的每個(gè)地址只能被讀，不能被寫的存儲(chǔ)器的大概分類。 ROM emulator（ROM模擬器） A debugging tool that takes the place ofor emulatesthe ROM on your target board. A ROM emulator acts very much like a debug monitor, except that it includes its own serial or network connection to the host. 一種在你的目標(biāo)板上代替或模擬ROM的調(diào)試工具。ROM模擬器動(dòng)作起來(lái)象一個(gè)除錯(cuò)監(jiān)視器，除了它包含自己連到主機(jī)上的串口或網(wǎng)絡(luò)外。 ROM monitor See debug monitor. RTOS（實(shí)時(shí)操作系統(tǒng)） RealTime Operating System. An operating system designed specifically for use in realtime systems. 實(shí)時(shí)操作系統(tǒng)。一種被特殊設(shè)計(jì)來(lái)用在實(shí)時(shí)系統(tǒng)中的操作系統(tǒng)。 race condition（競(jìng)爭(zhēng)狀態(tài)） A situation in which the oute of a program may be affected by the exact order in which the instructions are executed. Race conditions are only an issue where interrupts and/or preemption are possible and where critical sections exist. 一種程序運(yùn)行的結(jié)果可能被指令執(zhí)行的順序影響的情形。競(jìng)爭(zhēng)狀態(tài)僅僅有一種情況下產(chǎn)生，在此處中斷或（和）優(yōu)先搶占是充許的并且有一個(gè)臨界區(qū)存在。 realtime system（實(shí)時(shí)系統(tǒng)） Any puter system, embedded or otherwise, that has deadlines. The following question can be used to distinguish realtime systems from the rest: Is a late answer as bad, or even worse, than a wrong answer? In other words, what happens if the putation doesnt finish in time? If nothing bad happens, its not a realtime system. If someone dies or the mission fails, its generally considered hard realtime, which is meant to imply that the system has hard deadlines. Everything in between is soft realtime. 任何計(jì)算機(jī)系統(tǒng)，嵌入的或其他的，有一個(gè)死線。以下的問(wèn)題可經(jīng)被用來(lái)區(qū)分實(shí)時(shí)系統(tǒng)與其他的系統(tǒng)：“是遲到的回答壞，還是一個(gè)錯(cuò)誤的回答壞？”換句話說(shuō)，如果計(jì)算機(jī)沒(méi)有在指定時(shí)間內(nèi)完成它的工作會(huì)發(fā)生什么？如果什么也沒(méi)有發(fā)生，它不是一個(gè)實(shí)時(shí)系統(tǒng)。如果一些人死或任務(wù)失敗，它被認(rèn)為是“硬”實(shí)時(shí)系統(tǒng)，意思是系統(tǒng)有一個(gè)“硬”死線。介于兩者之間的是“軟”實(shí)時(shí)系統(tǒng)。 Recursive（遞歸） Said of software that calls itself. Recursion should generally be avoided in an embedded system, since it frequently requires a large stack. 自己調(diào)用自己的程序的說(shuō)法。遞歸一般在嵌入式系統(tǒng)中是不充許的，因?yàn)樗３Ｕ加写罅康亩褩？臻g。 Reentrant（可再入的） Said of software that can be executed multiple times simultaneously. A reentrant function can be safely called recursively or from multiple tasks. The key to making code reentrant is to ensure mutual exclusion whenever accessing global variables or shared registers. 可同時(shí)多次運(yùn)行的程序的說(shuō)法。可再入的函數(shù)可以被安全地遞歸調(diào)用或由多任務(wù)多次調(diào)用。使代碼可再入的關(guān)鍵在于確保在訪問(wèn)全局變量或共享寄存器時(shí)互斥現(xiàn)象發(fā)生。 Register（寄存器） A memory location that is part of a processor or an I/O device. In other words, its not normal memory. Generally, each bit or set of bits within the register controls some behavior of the larger device. 是處理器或I/O設(shè)備一部分的儲(chǔ)存器的地址。換句話說(shuō)，不是標(biāo)準(zhǔn)的儲(chǔ)存器。一般地，在寄存器控制每一二進(jìn)制位或二進(jìn)制位的集控制大量設(shè)備的一些行為。 Relocatable（可重定位的） A file containing object code that is almost ready for execution on the target. The final step is to use a locator to fix the remaining relocatable addresses within the code. The result of that process is an executable. 包含幾乎可以準(zhǔn)備好在目標(biāo)機(jī)上運(yùn)行的目標(biāo)代碼的文件。最后一步是使用定位程序去整理保留在代碼中的可重定位地址。這個(gè)步驟的結(jié)果是一個(gè)可執(zhí)行的程序。 reset address（重啟地址） The address from which the first instruction will be fetched after the processor is powered on or reset. 一個(gè)處理器上電或重啟后第一個(gè)指令能被從之取出來(lái)的地址。 reset code（重啟代碼） A small piece of code that is placed at the reset address. The reset code is usually written in assembly language and may simply be the equivalent of jump to the startup code. 一段被放置在重啟地址的代碼。重啟代碼一般用匯編語(yǔ)言編寫并且可能相當(dāng)簡(jiǎn)單，只是與”跳轉(zhuǎn)到開(kāi)始代碼”這樣的意思相同。 reset vector See reset address. S SRAM（靜態(tài)隨機(jī)訪問(wèn)儲(chǔ)存器） Static RandomAccess Memory. A type of RAM that retains its contents as long as the system is powered on. Data stored in an SRAM is lost when the system is powered down or reset. 靜態(tài)隨機(jī)訪問(wèn)儲(chǔ)存器。一種在系統(tǒng)上電時(shí)以保持它的內(nèi)容的儲(chǔ)存器。當(dāng)系統(tǒng)斷電或重啟時(shí)，保存在SRAM中的內(nèi)容將丟失。 Scheduler（調(diào)度程序） The part of an operating system that decides which task to run next. This decision is based on the readiness of each task, their relative priorities, and the specific scheduling algorithm implemented. 操作系統(tǒng)中決定下一次哪個(gè)任務(wù)運(yùn)行的那部分。決定基于每一個(gè)任務(wù)的就緒，它們的優(yōu)先級(jí)關(guān)系，和特殊調(diào)度算法的實(shí)現(xiàn)。 Semaphore（信號(hào)燈） A data structure that is used for intertask synchronization. Semaphores are usually provided by the operating system. 用于進(jìn)程間同步的數(shù)據(jù)結(jié)構(gòu)。信號(hào)燈常常由操作系統(tǒng)提供。 Simulator（仿真器） A debugging tool that runs on the host and pretends to be the target processor. A simulator can be used to test pieces o