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.


廣義地說，微型計算機控制系統(tǒng)（單片機控制系統(tǒng)）是用于處理信息的，這種被用于處理的信息可以是電話交談，也可以是儀器的讀數(shù)或者是一個企業(yè)的帳戶，但是各種情況下都涉及到相同的主要操作：信息的處理、信息的存儲和信息的傳遞。在常規(guī)的電子設(shè)計中，這些操作都是以功能平臺方式組合起來的，例如計數(shù)器，無論是電子計數(shù)器還是機械計數(shù)器，都要存儲當(dāng)前的數(shù)值，并且按要求將該數(shù)值增加1。一個系統(tǒng)例如采用計數(shù)器的電子鐘之類的任一系統(tǒng)要使其存儲和處理能力遍布整個系統(tǒng)，因為每個計數(shù)器都能存儲和處理一些數(shù)字。
現(xiàn)如今，以微處理器為基礎(chǔ)的系統(tǒng)從常規(guī)的處理方法中分離了出來，它將信息的處理，信息的存儲和信息的傳輸三個功能分離形成不同的系統(tǒng)單元。這種主要將系統(tǒng)分成三個主要單元的分離方法是馮-諾依曼在20世紀(jì)40年代所設(shè)想出來的，并且是針對微計算機的設(shè)想。從此以后基本上所有制成的計算機都是用這種結(jié)構(gòu)設(shè)計的，盡管他們包含著寬廣的物理形式與物理結(jié)構(gòu)，但從根本上來說他們均是具有相同基本設(shè)計的計算機。