2024年4月27日发(作者：)

单片机控制系统中英文对照外文翻译文献

(含：英文原文及中文译文)

英文原文

Microcomputer Systems

Electronic systems are used for handing information in the most general sense;

this information may be telephone conversation, instrument read or a company’s

accounts, but in each case the same main type of operation are involved: the

processing, storage 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 has 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 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 have 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/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 system’s behavior 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 software 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 machine. The

system is controlled by the microprocessor which supervises the transfer of

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.

Although only one storage section has been shown in the diagram, in practice

two distinct types of memory RAM and ROM are used. In each case, the word

‘memory’ is rather inappropriate since a computers memory is more like a filing

cabinet in concept; information is stored in a set of numbered ‘boxes’ and it is

referenced by the serial number of the ‘box’ in question.

Microcomputers 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 type

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 RAMs, 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 special 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,