1、大连科技 学院 2012 届本科生毕业设计 外文翻译 1 Microcomputer Systems Electronic systems are used for handing information in the most general sense； this information may be telephone conversation, instrument read or a companys accounts, but in each case the same main type of operation are involved: the processing, sto
2、rage and transmission of information. in conventional electronic design these operations are combined at the function level； for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters h
3、as its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers. Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different
4、 section of the system. This partitioning into three main functions was devised by Von Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they ha
5、ve all been of essentially the same basic design. In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I
6、/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the systems beh
7、avior would contain sections that performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of soft
8、ware engineering, and the similar problems of construction and maintenance which occur in conventional engineering are encountered when producing software. The figure1.1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the
9、machine. The system is controlled by the microprocessor which supervises the transfer of 大连科技 学院 2012 届本科生毕业设计 外文翻译 2 information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system. Microcomp
10、uters use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it was written, hence the expression random access memory. Another ty
11、pe of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor； these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RA
12、Ms, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of sp
13、ecial ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read Only Memories, EEPROMs. The microprocessor
14、processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission
15、 to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor. The microprocess
16、or processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmiss
17、ion to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out 大连科技 学院 2012 届本科生毕业设计 外文翻译 3 without directly involving the main
18、microprocessor. 1 First model 1.1 SCM the single chip microcomputer (Single Chip Microcomputer) stage Mainly seeking the best of the best single form of embedded systems architecture. Innovation model success, laying the SCM and general computer completely different path of development. In the open
19、road of independent development of embedded systems, Intel Corporation contributed. 1.2 MCU the micro-controller (Micro Controller Unit) stage The main direction of technology development: expanding to meet the embedded applications, the target system requirements for the various peripheral circuits
20、 and interface circuits, highlight the object of intelligent control.It involves the areas associated with the object system, therefore, the development of MCUs responsibility inevitably falls on electrical, electronics manufacturers. From this point of view, Intel faded MCU development has its obje
21、ctive factors. In the development of MCU, the most famous manufacturers as the number of Philips Corporation. Philips company in embedded applications, its great advantage, the MCS-51 single-chip micro-computer from the rapid development of the micro-controller. Therefore, when we look back at the p
22、ath of development of embedded systems, do not forget Intel and Philips in History. 2 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； Therefore, the d
23、evelopment of dedicated single chip SOC trend of the natural form. As the microelectronics, IC design, EDA tools development, application system based on MCU SOC design have greater development. Therefore, the understanding of the microcontroller chip microcomputer can be, extended to the single-chip micro-controller applications. 3 MCU applications SCM now permeate all areas of our lives, which is almost difficult to find traces of the field without SCM. Missile navigation equipment, aircraft, all types of instrument control, computer network communications and data transmission,
