说MCS-51是冯-诺依曼型,大多在PIC相关的**中

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awey 发表于 2007-10-30 22:13 | 显示全部楼层

说MCS-51是冯-诺依曼型,大多在PIC相关的**中

PIC单片机与MCS-51系列单片机的区别 &nbsp;<br />有三个主要特点:&nbsp;<br />(1)总线结构:MCS-51单片机的总线结构是冯-诺依曼型,计算机在同一个存储空间取指令和数据,两者不能同时进行;而PIC单片机的总线结构是哈佛结构,指令和数据空间是完全分开的,一个用于指令,一个用于数据,由于可以对程序和数据同时进行访问,所以提高了数据吞吐率。正因为在PIC单片机中采用了哈佛双总线结构,所以与常见的微控制器不同的一点是:程序和数据总线可以采用不同的宽度。数据总线都是8位的,但指令总线位数分别位12、14、16位。&nbsp;<br />(2)流水线结构:MCS-51单片机的取指和执行采用单指令流水线结构,即取一条指令,执行完后再取下一条指令;而PIC的取指和执行采用双指令流水线结构,当一条指令被执行时,允许下一条指令同时被取出,这样就实现了单周期指令。&nbsp;<br />(3)寄存器组:PIC单片机的所有寄存器,包括I/O口,定时器和程序计数器等都采用RAM结构形式,而且都只需要一个指令周期就可以完成访问和操作;而MCS-51单片机需要两个或两个以上的周期才能改变寄存器的内容。&nbsp;<br /><br /><br />
平常人 发表于 2007-10-30 22:16 | 显示全部楼层

不记得冯诺伊曼结构或哈佛结构是什么时候命名的?不过是

关键是要理解他们分别代表的结构是什么样的、有什么特点,就足够了,至于某种系统或某种机型处于哪种结构并不重要,冯·诺伊曼结构或哈佛结构只不过是一种称谓,便于我们**而已。<br /><br />再多说两句,记得上学时还没有这样较为明确的命名,但那时把所有程序和数据放到存储器中,运算过程按指令顺序进行的计算机系统(结构)通称为冯·诺伊曼计算机,因为这种计算方式是由冯·诺伊曼先生提出的。因此上面所说的冯·诺伊曼结构或哈佛结构都属于这个架构,而且今天绝大多数计算机也都是这种架构。<br /><br />这里就出现了一个问题,什么样的计算机结构不是冯·诺伊曼计算机呢?这也正是科学家们所研究的问题,比如讲曾经有段时间很多人在研究一种所谓数据流计算机,这种计算机有很多计算节点并构成一个网络,数据在这些节点间传递,根据数据所需的不同计算需求,它会经过具有相应计算能力的节点,整个的计算过程不是由程序驱动的而是由数据驱动的,这种结构与广义的冯·诺伊曼计算机完全不同。还有所谓神经元计算机等,今天的网络计算也具有这种节点网络的影子。<br /><br />说这么多,无非是想提醒各位在学习阶段不要纠缠于那些案例分析,要看到实质,要看到它背后的东西,要看到更广阔的天地,要能够举一反三,这样才能学到真谛。
HWM 发表于 2007-10-30 23:04 | 显示全部楼层

狭义而言,冯·诺伊曼和哈佛结构有着本质或理论上的差异

这里哈佛结构被定义为程序结构意义上不可变。<br /><br />冯·诺伊曼模型机在计算机基本算法理论上有着相当重要的地位,在此不可能展开。<br /><br />至于哈佛结构,这可涉及到早期的一位计算机工程师(Howard&nbsp;Hathaway&nbsp;Aiken在1944年为IBM公司研制MARK-1),他研发的一台计算机其程序使用“硬接线”的方法固化在当时的“ROM”中,形成了现在广为流传的“哈佛结构”。<br />
HWM 发表于 2007-10-30 23:54 | 显示全部楼层

下面给出Aiken的生平。

Howard&nbsp;Hathaway&nbsp;Aiken<br /><br />&nbsp;When&nbsp;Howard&nbsp;Hathaway&nbsp;Aiken&nbsp;was&nbsp;born&nbsp;in&nbsp;Hoboken,&nbsp;N.J.&nbsp;in&nbsp;1900,&nbsp;no&nbsp;one&nbsp;could&nbsp;know&nbsp;what&nbsp;a&nbsp;profound&nbsp;impact&nbsp;he&nbsp;would&nbsp;eventually&nbsp;have&nbsp;in&nbsp;the&nbsp;field&nbsp;of&nbsp;computer&nbsp;science&nbsp;because&nbsp;there&nbsp;was&nbsp;no&nbsp;field.&nbsp;In&nbsp;1900,&nbsp;Count&nbsp;Ferdinand&nbsp;von&nbsp;Zeppelin&nbsp;was&nbsp;preparing&nbsp;to&nbsp;wow&nbsp;the&nbsp;world&nbsp;with&nbsp;the&nbsp;first&nbsp;airships,&nbsp;and&nbsp;zippers&nbsp;were&nbsp;considered&nbsp;a&nbsp;novelty.&nbsp;Nobody&nbsp;at&nbsp;the&nbsp;time&nbsp;had&nbsp;radios&nbsp;or&nbsp;air&nbsp;conditioning,&nbsp;so&nbsp;something&nbsp;as&nbsp;complex&nbsp;as&nbsp;a&nbsp;computer&nbsp;was&nbsp;inconceivable&nbsp;to&nbsp;all&nbsp;but&nbsp;science&nbsp;fiction&nbsp;authors.&nbsp;Who&nbsp;would&nbsp;have&nbsp;guessed&nbsp;that&nbsp;Aiken&nbsp;would&nbsp;go&nbsp;on&nbsp;to&nbsp;conceive&nbsp;and&nbsp;create&nbsp;what&nbsp;until&nbsp;recently&nbsp;was&nbsp;regarded&nbsp;as&nbsp;the&nbsp;world抯&nbsp;first&nbsp;fully&nbsp;automated&nbsp;computer?<br /><br />Aiken&nbsp;graduated&nbsp;from&nbsp;the&nbsp;Arsenal&nbsp;Technical&nbsp;High&nbsp;School&nbsp;in&nbsp;Indianapolis,&nbsp;Ind.&nbsp;in&nbsp;1918,&nbsp;before&nbsp;parlaying&nbsp;his&nbsp;experience&nbsp;as&nbsp;a&nbsp;switchboard&nbsp;operator&nbsp;during&nbsp;high&nbsp;school&nbsp;into&nbsp;a&nbsp;bachelor抯&nbsp;of&nbsp;science&nbsp;degree&nbsp;in&nbsp;electrical&nbsp;engineering&nbsp;at&nbsp;the&nbsp;University&nbsp;of&nbsp;Wisconsin,&nbsp;Madison.&nbsp;Aiken&nbsp;worked&nbsp;for&nbsp;Madison&nbsp;Gas&nbsp;while&nbsp;he&nbsp;attended&nbsp;college,&nbsp;and&nbsp;then&nbsp;he&nbsp;took&nbsp;a&nbsp;position&nbsp;at&nbsp;Madison&nbsp;Gas&nbsp;as&nbsp;chief&nbsp;engineer&nbsp;after&nbsp;graduating,&nbsp;which&nbsp;he&nbsp;held&nbsp;until&nbsp;1928.&nbsp;He&nbsp;then&nbsp;went&nbsp;to&nbsp;work&nbsp;for&nbsp;Westinghouse&nbsp;Electrical&nbsp;and&nbsp;Manufacturing,&nbsp;and&nbsp;then&nbsp;Line&nbsp;Material.&nbsp;Aiken&nbsp;dreamed&nbsp;of&nbsp;creating&nbsp;a&nbsp;powerful&nbsp;electric&nbsp;calculator,&nbsp;and&nbsp;in&nbsp;1935&nbsp;he&nbsp;left&nbsp;for&nbsp;Harvard&nbsp;University.&nbsp;At&nbsp;Harvard,&nbsp;Aiken&nbsp;received&nbsp;a&nbsp;master抯&nbsp;degree&nbsp;in&nbsp;physics&nbsp;in&nbsp;1937,&nbsp;and&nbsp;he&nbsp;obtained&nbsp;a&nbsp;doctorate&nbsp;in&nbsp;physics&nbsp;in&nbsp;1939.<br /><br />During&nbsp;his&nbsp;education&nbsp;at&nbsp;Harvard,&nbsp;Aiken&nbsp;drew&nbsp;up&nbsp;plans&nbsp;for&nbsp;a&nbsp;programmable&nbsp;computer&nbsp;that&nbsp;could&nbsp;perform&nbsp;complex&nbsp;calculations,&nbsp;but&nbsp;he&nbsp;had&nbsp;no&nbsp;luck&nbsp;convincing&nbsp;anyone&nbsp;to&nbsp;give&nbsp;him&nbsp;the&nbsp;resources&nbsp;to&nbsp;build&nbsp;it&nbsp;until&nbsp;1939,&nbsp;when&nbsp;IBM&nbsp;president&nbsp;Thomas&nbsp;Watson&nbsp;agreed&nbsp;to&nbsp;fund&nbsp;the&nbsp;project.&nbsp;The&nbsp;result&nbsp;was&nbsp;the&nbsp;IBM&nbsp;ASCC&nbsp;(Automatic&nbsp;Sequence&nbsp;Controlled&nbsp;Calculator;&nbsp;more&nbsp;commonly&nbsp;called&nbsp;the&nbsp;Harvard&nbsp;Mark&nbsp;I),&nbsp;which&nbsp;at&nbsp;the&nbsp;time&nbsp;was&nbsp;considered&nbsp;the&nbsp;first&nbsp;automatic&nbsp;electromechanical&nbsp;digital&nbsp;computer.&nbsp;As&nbsp;far&nbsp;as&nbsp;anyone&nbsp;at&nbsp;the&nbsp;time&nbsp;was&nbsp;concerned,&nbsp;Aiken&nbsp;and&nbsp;his&nbsp;team&nbsp;had&nbsp;ushered&nbsp;in&nbsp;the&nbsp;computer&nbsp;age.&nbsp;The&nbsp;Mark&nbsp;I&nbsp;was&nbsp;completed&nbsp;in&nbsp;1943&nbsp;and&nbsp;fully&nbsp;operational&nbsp;in&nbsp;1944,&nbsp;running&nbsp;24&nbsp;hours&nbsp;a&nbsp;day&nbsp;for&nbsp;14&nbsp;years&nbsp;and&nbsp;processing&nbsp;three&nbsp;calculations&nbsp;per&nbsp;second.&nbsp;The&nbsp;Mark&nbsp;II,&nbsp;Mark&nbsp;III,&nbsp;and&nbsp;Mark&nbsp;IV&nbsp;followed&nbsp;the&nbsp;Mark&nbsp;I,&nbsp;with&nbsp;Aiken&nbsp;overseeing&nbsp;all&nbsp;of&nbsp;the&nbsp;projects&nbsp;between&nbsp;1944&nbsp;and&nbsp;1952.<br /><br />As&nbsp;if&nbsp;his&nbsp;legacy&nbsp;wasn抰&nbsp;already&nbsp;strong&nbsp;enough&nbsp;to&nbsp;garner&nbsp;him&nbsp;a&nbsp;place&nbsp;as&nbsp;one&nbsp;of&nbsp;the&nbsp;most&nbsp;important&nbsp;computer&nbsp;scientists&nbsp;of&nbsp;all&nbsp;time,&nbsp;Aiken&nbsp;founded&nbsp;the&nbsp;Harvard&nbsp;Computation&nbsp;Laboratory&nbsp;in&nbsp;1947,&nbsp;where&nbsp;he&nbsp;established&nbsp;the&nbsp;first&nbsp;computer&nbsp;science&nbsp;program&nbsp;and&nbsp;served&nbsp;as&nbsp;director&nbsp;until&nbsp;his&nbsp;retirement&nbsp;in&nbsp;1961.&nbsp;After&nbsp;a&nbsp;move&nbsp;to&nbsp;Florida,&nbsp;Aiken&nbsp;took&nbsp;a&nbsp;position&nbsp;at&nbsp;Miami&nbsp;University&nbsp;as&nbsp;professor&nbsp;of&nbsp;information&nbsp;technology&nbsp;in&nbsp;1961,&nbsp;a&nbsp;post&nbsp;he&nbsp;held&nbsp;until&nbsp;1973,&nbsp;the&nbsp;year&nbsp;he&nbsp;passed&nbsp;away.&nbsp;During&nbsp;that&nbsp;time&nbsp;Aiken&nbsp;started&nbsp;his&nbsp;own&nbsp;consulting&nbsp;firm,&nbsp;Howard&nbsp;Aiken&nbsp;Industries,&nbsp;and&nbsp;set&nbsp;up&nbsp;both&nbsp;a&nbsp;computer&nbsp;science&nbsp;program&nbsp;and&nbsp;a&nbsp;computing&nbsp;center&nbsp;at&nbsp;Miami&nbsp;University.<br /><br />He&nbsp;was&nbsp;awarded&nbsp;the&nbsp;first&nbsp;Harry&nbsp;M.&nbsp;Goode&nbsp;Memorial&nbsp;Award&nbsp;by&nbsp;the&nbsp;IEEE&nbsp;(Institute&nbsp;of&nbsp;Electrical&nbsp;and&nbsp;Electronic&nbsp;Engineers)&nbsp;Computer&nbsp;Society&nbsp;in&nbsp;1964&nbsp;with&nbsp;the&nbsp;citation:&nbsp;揊or&nbsp;his&nbsp;original&nbsp;contribution&nbsp;to&nbsp;the&nbsp;development&nbsp;of&nbsp;the&nbsp;automatic&nbsp;computer,&nbsp;leading&nbsp;to&nbsp;the&nbsp;first&nbsp;large-scale&nbsp;general&nbsp;purpose&nbsp;automatic&nbsp;digital&nbsp;computer.?&nbsp;The&nbsp;award&nbsp;recipients&nbsp;are&nbsp;chosen&nbsp;on&nbsp;the&nbsp;basis&nbsp;of&nbsp;their&nbsp;achievements&nbsp;in&nbsp;the&nbsp;information&nbsp;processing&nbsp;field,&nbsp;either&nbsp;a&nbsp;single&nbsp;contribution&nbsp;or&nbsp;an&nbsp;accumulation&nbsp;of&nbsp;important&nbsp;contributions.<br /><br />The&nbsp;IEEE&nbsp;awarded&nbsp;Aiken&nbsp;with&nbsp;an&nbsp;Edison&nbsp;Medal&nbsp;in&nbsp;1970,&nbsp;揻or&nbsp;a&nbsp;meritorious&nbsp;career&nbsp;of&nbsp;pioneering&nbsp;contributions&nbsp;to&nbsp;the&nbsp;development&nbsp;and&nbsp;application&nbsp;of&nbsp;large-scale&nbsp;digital&nbsp;computers&nbsp;and&nbsp;important&nbsp;contributions&nbsp;to&nbsp;education&nbsp;in&nbsp;the&nbsp;digital&nbsp;computer&nbsp;field.?This&nbsp;award&nbsp;is&nbsp;given&nbsp;out&nbsp;in&nbsp;recognition&nbsp;of&nbsp;a&nbsp;person抯&nbsp;high&nbsp;attainments,&nbsp;over&nbsp;a&nbsp;certain&nbsp;number&nbsp;of&nbsp;years,&nbsp;in&nbsp;electrical&nbsp;engineering,&nbsp;electrical&nbsp;science,&nbsp;or&nbsp;the&nbsp;electrical&nbsp;arts.<br /><br />The&nbsp;IEEE&nbsp;Computer&nbsp;Society&nbsp;also&nbsp;lists&nbsp;Aiken&nbsp;as&nbsp;Charter&nbsp;Recipient&nbsp;of&nbsp;its&nbsp;Computer&nbsp;Pioneer&nbsp;Award.&nbsp;This&nbsp;award&nbsp;is&nbsp;presented&nbsp;to&nbsp;the&nbsp;individual&nbsp;that&nbsp;makes&nbsp;significant&nbsp;contributions&nbsp;to&nbsp;concepts&nbsp;and&nbsp;developments&nbsp;in&nbsp;the&nbsp;electronic&nbsp;computer&nbsp;field.<br /><br />As&nbsp;it&nbsp;turns&nbsp;out,&nbsp;Aiken&nbsp;and&nbsp;his&nbsp;team&nbsp;at&nbsp;Harvard&nbsp;were&nbsp;not&nbsp;the&nbsp;first&nbsp;people&nbsp;to&nbsp;create&nbsp;an&nbsp;electromechanical&nbsp;digital&nbsp;computer.&nbsp;German&nbsp;inventor&nbsp;Konrad&nbsp;Zuse抯&nbsp;advanced&nbsp;Z3&nbsp;machine&nbsp;was&nbsp;completed&nbsp;in&nbsp;1941.&nbsp;Zuse抯&nbsp;computer&nbsp;was&nbsp;developed&nbsp;completely&nbsp;independently&nbsp;of&nbsp;Aiken抯,&nbsp;however,&nbsp;and&nbsp;few&nbsp;were&nbsp;aware&nbsp;of&nbsp;its&nbsp;existence&nbsp;until&nbsp;well&nbsp;after&nbsp;World&nbsp;War&nbsp;II.&nbsp;Although&nbsp;the&nbsp;Mark&nbsp;I&nbsp;wasn抰&nbsp;completed&nbsp;until&nbsp;1944,&nbsp;it&nbsp;must&nbsp;be&nbsp;remembered&nbsp;that&nbsp;Aiken抯&nbsp;design&nbsp;had&nbsp;a&nbsp;much&nbsp;more&nbsp;far-ranging&nbsp;influence&nbsp;in&nbsp;the&nbsp;field&nbsp;of&nbsp;computing&nbsp;than&nbsp;Zuse抯&nbsp;design&nbsp;had,&nbsp;by&nbsp;simple&nbsp;virtue&nbsp;of&nbsp;more&nbsp;people&nbsp;knowing&nbsp;about&nbsp;it.&nbsp;The&nbsp;fact&nbsp;that&nbsp;Zuse&nbsp;built&nbsp;his&nbsp;machine&nbsp;first&nbsp;also&nbsp;does&nbsp;not&nbsp;diminish&nbsp;the&nbsp;reputation&nbsp;of&nbsp;Aiken&nbsp;and&nbsp;his&nbsp;team,&nbsp;who&nbsp;were&nbsp;unaware&nbsp;of&nbsp;Zuse抯&nbsp;accomplishments&nbsp;while&nbsp;work&nbsp;commenced&nbsp;on&nbsp;the&nbsp;Mark&nbsp;I.&nbsp;&nbsp;<br />
ri811127 发表于 2007-10-31 10:50 | 显示全部楼层

耐着性子我看了又看

唉呀呀,<br />刚看了几篇而已<br />就感觉气血翻涌,心中止不住的烦恶,手发抖,脚发软,身子发凉~~~<br />我知道这是到了紧要关头了,要冲关了,<br />所以屏气凝神,强抑种种不适之感,耐着性子往下翻~~<br /><br />终于,长翅膀的人出现了,醍醐灌顶,涓涓细流在走火入魔的一刹那挽救了俺~~心中不快稍释,我是看了又看,翻了又翻~~~<br /><br />不过话说回来,真没看明白```恁就好事做到底,把口诀传了俺得了-__-!!<br /><br />顺便恳求您一定用口语白话中国字,<br /><br /><br />38楼43楼也说的真好,赞先~!不过我又糊涂了,<br />引用<br />&quot;<br />再多说两句,记得上学时还没有这样较为明确的命名,但那时把所有程序和数据放到存储器中,运算过程按指令顺序进行的计算机系统(结构)通称为冯·诺伊曼计算机<br />&quot;<br />如上所述那两者好象就没什么不同了吧<br /><br />我的理解就是,冯在一起,哈不在一起<br />我的结论就是,51是这么转的,PIC是那么转的,管它叫什么鸟名字,<br /><br />恳切请批
xwj 发表于 2007-10-31 10:57 | 显示全部楼层

哈哈,LS神功有成,不错

都是外国人的名字,<br />管他怎么叫呢,俺只要知道有什么特点和怎么用不就行了?<br /><br /><br />呵呵^_^
HWM 发表于 2007-10-31 13:52 | 显示全部楼层

呵呵,确实都是外国人的名字,从Turing到Aiken再到von Neumann

可惜的是这些名字都和计算机基础理论紧密联系在一起,而技术上看这些人的思想毫无难度,却为现代计算机技术奠定了扎实的基础(将来的数据流和并行计算系统也不例外)。<br />更可惜的是有多少业内国人在这些最为基本的领域中能执着探索,而这却是真正具有价值的“中国创造”。<br />
mcs_89c51 发表于 2007-10-31 15:35 | 显示全部楼层

12

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br /><br /><br /><br /><br /><br /><br /><br /><br /><br />0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
yanxuyuan 发表于 2007-11-1 10:09 | 显示全部楼层

都不用上班了

  
 楼主| quguoli81 发表于 2007-11-1 15:16 | 显示全部楼层

收贴

再吵下去没有意义!<br />发贴的目的是弄清一个问题,不是用来吵架,炫耀,以及……<br />现在成这样,即使大家都承认51是哈佛结构,51也跑不过酷睿,没有意义,所以收贴。免得耽误大家的宝贵时间!
mercell 发表于 2007-11-8 12:00 | 显示全部楼层

FPGA

FPGA就是一种常见的非von&nbsp;Neumann结构的计算平台,它的潜力现在还远没有发掘出来。顺便,NIOS等软核CPU,实质上就是FPGA计算平台上搭建的,模仿冯·诺伊曼架构的虚拟机。
兰天白云 发表于 2007-11-8 12:18 | 显示全部楼层

我从不管是什么总线,只看谁的效率高,谁便宜

实用主义
HWM 发表于 2007-11-8 12:19 | 显示全部楼层

FPGA != CPU

  
hzp_58 发表于 2007-11-8 18:46 | 显示全部楼层

51属于冯诺依曼结构

51属于冯诺依曼结构<br />PIC是哈佛结构
 楼主| quguoli81 发表于 2007-11-9 14:14 | 显示全部楼层

看来,帖子应该改成讨论冯诺依曼结构和哈佛结构的优劣!

  
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