【正文】 分配地址當然也是以電信號的形式給出的，由于存儲單元比較多，所以，用于地址分配的線也較多，這些線被稱為地址總線。 單片機在汽車電子中的應用非常廣泛，例如汽車中的發(fā)動機控制器，基于 CAN 總線的汽車發(fā)動機智能電子控制器， GPS 導航系統 ， abs 防抱死系統，制動系統等等。 某些專用單片機設計用于實現特定功能，從而在各種電路中進 行模塊化應用，而不要求使用人員了解其內部結構。 用單片機可以構成形式多樣的控制系統、數據采集系統。因此，單片機的學習、開發(fā)與應用將造就一批計算機應用與智能化控制的科學家、工程師。因此，對單片機的理解可以從單片微型計算機、單片微控制器延伸到單片應用系統。 Philips 公司以其在嵌入式應用方面的巨大優(yōu)勢，將 MCS51 從單片微型計算機迅速發(fā)展到微控制器。 即微控制器（ Micro Controller Unit）階段，主要的技術發(fā)展方向是：不斷擴展?jié)M足嵌入式應用時，對象系統要求 的各種外圍電路與接口電路，突顯其對象的智能化控制能力。 單片機歷史 單片機誕生于 20世紀 70年代末，經歷了 SCM、 MCU、 SoC 三大階段。現在，這種單片機的使用領域已十分廣泛，如 智能儀表 、實時工控、通訊設備、導航 系統、家用電器等。這種計算機就是把智能賦予各種機械的單片機（亦稱微控制器）。 可以說，二十世紀跨越了三個 “電 ”的時代，即電 氣時代、電子時代和現已進入的電腦時代。一個不是很復雜的功 能要是用美國 50 年代開發(fā)的 74 系列，或者 60 年代的 CD4000 系列這些純硬件來搞定的話，電路一定是一塊大 PCB 板！但是如果要是用美國 70 年代成功投放市場的系列單片機，結果就會有天壤之別！只因為單片機的通過你編寫的程序可以實現高智能，高效率，以及高可靠性！ 由于單片機對成本是敏感的，所以目前占統治地位的軟件還是最低級匯編 語言，它是除了二進制機器碼以上最低級的語言了，既然這么低級 為什么還要用呢？很多高級的語言已經達到了可視化編程的水平為什么不用呢？原因很簡單，就是單片機沒有家用計算機那樣的 CPU，也沒有像硬盤那樣的海量存儲設備。我們現在用的全自動滾筒洗衣機、排煙罩、 VCD 等等的家電里面都可以看到它的身影！ ......它主要是作為控制部分的核心部件。概括的講：一塊芯片就成了一臺計算機。而個人電腦中也會有為數不少的單片機在工作。 單片機比專用處理器更適合應用于 嵌入式系統 ，因此它得到了最多的應用。而傳統的 8 位單片機的性能也得到了飛速提高，處理能力比起 80年代提高了數百倍?；谶@一系統的單片機系統直到現在還在廣泛使用。 INTEL 的 Z80 是最早按照這種思想設計出的處理器，從此以后，單片機和專用處理 器的發(fā)展便分道揚鑣。 , has a special expertise in its services unit, that is, the stack pointer SP, whenever a PUSH instruction execution, SP on (in the Based on the original value) automatically add 1, whenever the implementation of a POP instruction, SP will (on the basis of the original value) automatically by 1. As the SP values can be changed with the instructions, so long as the beginning of the process to change the value of the SP, you can set the stack memory unit required, such as the program begins, with an MOV SP, 5FH instructions When set on the stack starting from the memory unit 60H unit. There is always the beginning of the general procedure with such a directive to set the stack pointer, because boot, SP initial value of 07H, 08H This unit from the beginning to stack next, and 08H to 1FH 8031 is the second in the region, three or four working register area, often used, this will lead to confusion of data. Different authors when writing programs, initialize the stack is not exactly the same directive, which is the author39。, and the stack has a special data transmission instructions that39。 units started, that is: the system must exist in ROM 0000 39。 as a general purpose I / O port to use. You can arrange the order of a SETB 39。 is also not a 39。and 39。s responsibility inevitably falls on electrical, electronics manufacturers. From this point of view, Intel faded MCU development has its objective factors. In the development of MCU, the most famous manufacturers as the number of Philips Corporation. Philips pany in embedded applications, its great advantage, the MCS51 singlechip microputer from the rapid development of the microcontroller. Therefore, when we look back at the path of development of embedded systems, do not fet Intel and Philips in History. Embedded Systems Embedded system microcontroller is an independent development path, the MCU important factor in the development stage, is seeking applications to maximize the solution on the chip。s with the United States developed 74 series, or the 6039。 外文資料譯文 Singlechip SCM is also known as microcontroller (Microcontroller Unit), monly used letters of the acronym MCU that it was first used in industrial control. Only a single chip by the CPU chip developed from a dedicated processor. The first design is by a large number of peripherals and CPU on a chip in the puter system, smaller, more easily integrated into a plex and demanding on the volume control device which. INTEL39。s largest puter. Modern human life used in almost every piece of electronic and mechanical products will be integrated single chip. Phone, telephone, calculator, home appliances, electronic toys, handheld puters and puter accessories such as a mouse with a 12 in both the Department of SCM. Personal puter will have a large number of SCM in the work. General car with more than 40 SCM, plex industrial control systems may even have hundreds of SCM in the same time work! SCM is not only far exceeds the number of PC and other puting the sum, or even more than the number of human beings Single chip, also known as singlechip microcontroller, it is not plete a certain logic chips, but to a puter system integrated into a chip. Equivalent to a microputer, and puter than just the lack of a microcontroller I / O devices. General talk: a chip bees a puter. Its small size, light weight, cheap, for the study, application and development of facilities provided. At the same time, learning to use the MCU is to understand the principle and structure of the puter the best choice. SCM and the puter functions internally with similar modules, such as CPU, memory, parallel bus, the same effect as well, and hard disk memory devices, and different is its performance of these ponents w