单片机系统外文翻译.doc

外文原文 Microcomputer systems Electronic systems are used for handing information in the most general sense ; this information may be telephone conversation , instrument read or a companys 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 systems 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