一、概述 MC68020是莫托洛拉公司继开发68000系列微处理机后于1984年推出的第一个全32位微处理机。它兼用CMOS和NMOS工艺,集成度为20万晶体管/片,功耗只有1～1.5W。采用100条引脚方阵(PGA)直插式封装。 68020的设计目标是保持与68000系列用户目标码的互换性,性能比68000提高4～6倍。所以该公司采取了一系列技术措施:强化并扩展68000指令系统,增加若干新指令,扩充以变址为中心的寻址方式,增加四种数据型式,强化高级语言支持。片内设置高速指令缓冲存储器和动态确定总线宽度的总线宽度切换机 I. Overview The MC68020 is the first all-32 microprocessor introduced by Motorola in 1984, following the development of the 68000 series of microprocessors. It uses both CMOS and NMOS technology, the integration of 200,000 transistors / piece, power consumption is only 1 ~ 1.5W. 100-pin square array (PGA) in-line package. The 68020 is designed to maintain interchangeability with the 68000 family of user-specific code, delivering up to 4x more performance than the 68000. So the company took a series of technical measures to strengthen and expand the 68000 instruction system, add a number of new directives, expand address-centric addressing, add four data types and strengthen high-level language support. Chip set high-speed instruction buffer memory and bus width to determine the width of the bus width switch