loongson_as.htm

龙芯汇编语言入门

lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN></B><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">用逻辑门电路（具体实现时，则经历了电子管，晶体管和集成电路三代电子技术），在时钟节拍的指挥下，用硬连线执行指令。早期给电脑编写程序，是直接用机器指令写程序。但很快，程序员们就研究出用助记符号来表示指令，这样一来，程序要容易写和读懂了，这种用汇编语言写程序的编写程序的方式，直到现在还在使用，因为每一种指令都有汇编语言助记符号相对应，可以最精确地控制</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">CPU</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的指令执行，不象高级语言，一条语句对应很多条机器指令，编译器生成的二进制可执行程序代码，臃肿，执行速度慢，占用更多内存。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">人写的代码总是最短和最快的，所以学习汇编程序设计，主要是为了写操作系统的底层模块，开发嵌入式应用的驱动程序和接口，以及为了设计编译器。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><B><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">第二代指令系统</SPAN></B><B><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">(CISC)</SPAN></B><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">是微程序方式，即一条指令被译码电路译成一条或多条微指令，微指令用逻辑门电路，在时钟节拍的指挥下，用硬连线执行指令。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">为什么要使用微程序方式来执行计算机的指令？</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">因为此时的计算机的的程序设计手段中，出现了高级语言（主要是</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">FORTRAN</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">和</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">COBOL</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">）。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">此外系统程序则有了多道程序设计的操作系统。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">对于高级语言，研究人员发现可以设计一些复杂的指令，用微程序实现后可以提高用高级语言的编译器编译出来的代码的执行效率和简化编译器的设计。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">而且微程序可以动态装入计算机的微程序存储器中，从而把计算机变成一台虚机器，适合执行</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">COBOL</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的叫</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">COBOL</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">机，适合执行</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">FORTRAN</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的则叫</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">FORTRAN</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">机，等等。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">对于操作系统，用微程序实现的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">OS</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">专用指令，就叫作</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">“</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">原语</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">”</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">这种微程序设计的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">CPU</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，看上去是很精巧的，因此被广泛使用，从</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">60</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">年代末开始，大型机基本都是微程序设计的。最初的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">4</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">位微处理器和</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">8</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">位的微处理器是用硬连线执行指令。而从</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">16</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">位处理器开始，微处理器也采用了微程序设计。最有名的三大</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">16</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">位处理器，有两种采用微程序设计：</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">8086</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">和</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">68000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，而</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">Z-8000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">则是采用硬连线执行指令。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">当年专家们的评估报告是</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">68000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">最先进。但也有专家认为，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">68000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">集成度太高，中国的集成电路厂造不出这样的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">CPU</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，因此可以先仿制</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">Z-8000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">。确实有陕西的研究机构仿造出了</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">Z-8000</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">。后来，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">8086</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">也有中国的研究所仿制成功。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">早期的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">32</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">位处理器，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">80386</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">68020</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">68030</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">32032</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">等也都是微程序设计。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><B><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">第三代指令系统</SPAN></B><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">就是</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">了。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">IBM</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">首先提出</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">设计思想，目的就是让</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">处理器能在优化编译器的帮助下，生成的目标代码，在运行速度上可以和手工编写的代码相当或更快（因为编译器可以利用流水线调度技术，超标量技术等，做到一个时钟周期可以执行一条以上的指令）。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR>RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的关键就是流水线执行指令的技术。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR>RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">指令种类较少，这样完成同样的功能，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">X86</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">用一条指令，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">RISC</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">就要用几条指令来完成。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><B><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">第四代指令系统有两种：</SPAN></B><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">一种是目前</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">X86</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">CISC=&gt;RISC-op</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">，</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">RISC-op</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">乱序超标量执行。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">另一种是</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">IA-64</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">的</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">VLIW</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">还有就是</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">SIMD</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">方式的多媒体指令。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">先写到这里吧，本文是杂文体，没有按教材方式写。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">下次再修改补充了。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">最新版本可以看</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><A 
href="http://www.lemote.com/wiki" target=_blank><SPAN 
style="COLOR: #154ba0; TEXT-DECORATION: none; mso-bidi-font-size: 12.0pt; text-underline: none">http://www.lemote.com/wiki</SPAN></A></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">《龙芯汇编语言程序设计入门》</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">在</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">wiki</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">上的那个版本是教材体。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt">wiki</SPAN><SPAN 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: SimSun; mso-ascii-font-family: Tahoma; mso-hansi-font-family: Tahoma; mso-bidi-font-family: Tahoma; mso-font-kerning: 0pt">是开放的，大家都可以来修改和补充，不断完善。</SPAN><SPAN 
lang=EN-US 
style="FONT-SIZE: 9pt; COLOR: #333333; FONT-FAMILY: Tahoma; mso-font-kerning: 0pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal 
style="MARGIN-BOTTOM: 12pt; TEXT-ALIGN: left; mso-pagination: widow-orphan" 
align=left><SPAN 
style="FONT-SIZE: 12pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">为汇编程序的翻译成机器码和运行二进制可执行文件准备一个系统。<SPAN 
lang=EN-US><o:p></o:p></SPAN></SPAN></P>
<P class=MsoNormal 
style="MARGIN-BOTTOM: 12pt; TEXT-ALIGN: left; mso-pagination: widow-orphan" 
align=left><SPAN lang=EN-US 
style="FONT-SIZE: 24pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">Q</SPAN><SPAN 
style="FONT-SIZE: 24pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">：如果我想上机实践，但没有机器，怎么办？<SPAN 
lang=EN-US><BR>A</SPAN>：你可以使用一台虚拟的龙芯。</SPAN><SPAN lang=EN-US 
style="FONT-SIZE: 12pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 12pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">这台虚拟的龙芯是一个运行在<SPAN 
lang=EN-US>X86</SPAN>或别的硬件平台上的模拟器。在这个模拟器上，你可以安装<SPAN 
lang=EN-US>Debian</SPAN>，可以用<SPAN lang=EN-US>vi</SPAN>编辑源程序，可以运行<SPAN 
lang=EN-US>as</SPAN>来汇编你的源码，使用<SPAN 
lang=EN-US>ld</SPAN>完成连接，生成可执行的二进制代码文件。最后运行这个二进制代码文件。<SPAN 
lang=EN-US><BR></SPAN></SPAN><SPAN 
style="FONT-SIZE: 24pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">你还可以使用这个模拟器来学习和使用<SPAN 
lang=EN-US>Linux</SPAN>。</SPAN><SPAN lang=EN-US 
style="FONT-SIZE: 12pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt"><BR></SPAN><SPAN 
style="FONT-SIZE: 12pt; FONT-FAMILY: SimSun; mso-bidi-font-family: SimSun; mso-font-kerning: 0pt">前段时间，愚蠢小猪说：“建议“龙芯”出版一本书，详细介绍“龙芯”的结构、特点、使用范例。当然这样类型的计算机书很多，谈不上什么特色。关键的是这本书要附带一个“龙芯”的实验板和配套光盘，“龙芯”应用的最小配置，性能要求不高：主频有<SPAN 
lang=EN-US>100MHz</SPAN>就足够了，一个网络接口，配<st1:chmetcnv w:st="on" UnitName="m" 
SourceValue="32" HasSpace="False" Negative="False" NumberType="1" TCSC="0"><SPAN 
lang=EN-US>32M</SPAN></st1:chmetcnv>的<SPAN 
lang=EN-US>SDRAM</SPAN>（现在也便宜），再配一个<SPAN lang=EN-US>SD</SPAN>的 
读卡器，为了降低成本不支付<SPAN lang=EN-US>SD</SPAN>卡的许可，使用<SPAN 
lang=EN-US>SPI</SPAN>模式读写<SPAN lang=EN-US>SD</SPAN>卡就足够了。这个最小系统就能够运行<SPAN 
lang=EN-US>Linux</SPAN>了，可以构造一个基本的网络服务器。当然，也可以运行其它操作系统。<SPAN 
lang=EN-US><BR></SPAN>为了降低成本，只安装表面贴装元件，其它的大型元件、接插件机<SPAN 
lang=EN-US>5V</SPAN>电源等，由读者自行选配。整本书的定价控制在大约<SPAN 
lang=EN-US>100</SPAN>元，最高最好不要超过<SPAN lang=EN-US>200 
</SPAN>元。这价格我是根据日本的行情，中国的情况可能有所不同。日本的书价折算成<SPAN lang=EN-US>RMB</SPAN>大约<SPAN 
lang=EN-US>100-200</SPAN>元，附录实验板的也差不多这个价，实验板算是白送的。当然，日本的实验板能跑起<SPAN 
lang=EN-US>TRON</SPAN>就可以了，配置没有这么高，主频<SPAN lang=EN-US>50MHz</SPAN>，内存<SPAN 
lang=EN-US>512K</SPAN>。<SPAN 
lang=EN-US><BR></SPAN>“龙芯”要在江湖上立足，需要出手大方，大胆的送。当然，这种价格出售，会亏本，“龙芯”的经费有限，席梦丝的钱花多了会肉疼。可以考虑拉些广告赞助，实验板上印一些厂商的名字，书里面插大量的广告，<SPAN 
lang=EN-US>1/3</SPAN>的篇幅是广告问题不大。最好拉一些政府部委的赞助，比如教育部吧，我帮你搞教育，你也得表示点吧。书发行完后，实验板继续卖，当然就需要原价了。开始阶段，“龙芯”不要太贪，保本就可以了。还可以继续发行配套的系列丛书，介绍基于此试验板的应用，还可以继续附录配套的扩展实验板，比如图形声音的接口，这个最基本的“龙芯”就可以逐步成长为一完整的系统。”<SPAN 
lang=EN-US> <BR><A href="http://www.lemote.com/bbs/viewthread.php?tid=9528" 
target=_blank>http://www.lemote.com/bbs/viewthread.php?tid=9528</A><BR></SPAN>胶林对此的点评是<SPAN 
lang=EN-US>:</S