The monolithic integrated circuit was born in the late-1970s, has experienced SCM, MCU, the SOC three big stages.
1. SCM namely monolithic microcomputer (Single Chip Microcomputer) the stage, mainly seeks the best monolithic shape embedded system's best architecture. “the innovation pattern” obtains successfully, has established SCM and the general-purpose calculator completely different development path. In founds on the embedded system independent development path, Intel Corporation has lasting achievements.
2. MCU namely micro controller (Micro Controller Unit) the stage, the main technological development direction is: Expands unceasingly when satisfies the embedded application, the object system request's each kind of peripheral circuit and the interface circuit, underline its object intellectualization control. It involves the domain is related with the object system, therefore, develops the MCU heavy responsibility to fall inevitably on electrical, the electronic technology factory. Looking from this angle, Intel fades out the MCU development also to have its objective factor gradually. Is developing the MCU aspect, the most famous factory family belongings count Philips Corporation. Philips Corporation by it in embedded application aspect huge superiority, MCS-51 from monolithic microcomputer rapidly expand to micro controller. Therefore, when we review the embedded system development path, do not

單片機誕生于20世紀70年代末，經(jīng)歷了SCM、MCU、SOC三大階段。
1.SCM即單片微型計算機（Single Chip Microcomputer）階段，主要是尋求最佳的單片形態(tài)嵌入式系統(tǒng)的最佳體系結(jié)構(gòu)?！皠?chuàng)新模式”獲得成功，奠定了SCM與通用計算機完全不同的發(fā)展道路。在開創(chuàng)嵌入式系統(tǒng)獨立發(fā)展道路上，Intel公司功不可沒。
2.MCU即微控制器（Micro Controller Unit）階段，主要的技術(shù)發(fā)展方向是：不斷擴展?jié)M足嵌入式應用時，對象系統(tǒng)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。它所涉及的領(lǐng)域都與對象系統(tǒng)相關(guān)，因此，發(fā)展MCU的重任不可避免地落在電氣、電子技術(shù)廠家。從這一角度來看，Intel逐漸淡出MCU的發(fā)展也有其客觀因素。在發(fā)展MCU方面，最著名的廠