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基于单片机的温度控制系统(完整资料)(可以直接使用,可编辑优秀版资料,欢迎下载)
基于单片机的温度控制系统(完整资料)(可以直接使用,可编辑优秀版资料,欢迎下载)毕业论文设计基于51单片机的温度控制系统摘要在日常生活中温度在我们身边无时不在,温度的控制和应用在各个领域都有重要的作用。很多行业中都有大量的用电加热设备,和温度控制设备,如用于报警的温度自动报警系统,热处理的加热炉,用于融化金属的坩锅电阻炉及各种不同用途的温度箱等,这些都采用单片机技术,利用单片机语言程序对它们进行控制。而单片机技术具有控制和操作使用方便、结构简单便于修改和维护、灵活性大且具有一定的智能性等特点,可以精确的控制技术标准,提高了温控指标,也大大的提高了产品的质量和性能。由于单片机技术的优点突出,智能化温度控制技术正被广泛地采用。本文介绍了基于单片机AT89C51的温度控制系统的设计方案与软硬件实现。采用温度传感器DS18B20采集温度数据,7段数码管显示温度数据,按键设置温度上下限,当温度低于设定的下限时,点亮绿色发光二极管,当温度高于设定的上限时,点亮红色发光二极管。给出了系统总体框架、程序流程图和Protel原理图,并在硬件平台上实现了所设计功能。关键词:单片机温度控制系统温度传感器AbstractIndailylife,thetemperatureinoursidetheever-present,thecontrolofthetemperatureandtheapplicationinvariousfieldsallhaveimportantrole。Manyindustrytherearealargenumberofelectricheatingequipment,andthetemperaturecontrolequipment,suchasusedforalarmautomatictemperaturealarmsystems,heattreatmentfurnace,usedtomeltmetalcrucibleresistancefurnace,andallkindsofdifferentUSESoftemperatureboxandsoon,theseusingsinglechipmicrocomputer,usingsinglechipcomputerlanguageprogramtocontrolthem.Andsingle-chipmicrocomputertechnologyhascontrolandconvenientinoperation,easytomodifyandmaintenanceofsimplestructure,flexibilityislargeandhassomeoftheintelligenceandothercharacteristics,wecanaccuratelycontroltechnologystandardtoimprovethetemperaturecontrolindex,alsogreatlyimprovethequalityoftheproductsandperformance.Becauseoftheadvantagesofthesinglechipmicrocomputerintelligenttemperaturecontroltechnologyoutstanding,isbeingwidelyadopted。ThispaperintroducesthetemperaturecontrolbasedonsinglechipmicrocomputerAT89C51designschemeofthesystemandthehardwareandsoftwareimplementation。ThetemperaturesensorDS18B20collectiontemperaturedata,7periodofdigitalpipedisplay,theupperandlowerlimitsoftemperaturebuttonwhentemperaturebelowthesettingofthelowerlimit,lightgreenleds,whenthetemperatureishigherthanthesetonthelimit,lightredleds.Giventhesystemframeworkandprogramflowchartandprinciplechart,andinProtelhardwareplatformtorealizethefunctionofthedesign.Keywords:SCMTemperaturecontrolsystemTemperaturesensors目录TOC\o”1—3"\h\z\uHYPERLINK\l”_Toc295836733"摘要I第一章前言1HYPERLINK\l”_Toc295836736”1。1温度控制系统设计发展历史及意义1HYPERLINK\l”_Toc295836737”1.2温度控制系统的目的11。3温度控制系统完成的功能1第二章总体设计方案2HYPERLINK\l”_Toc295836740”2。1方案一2_Toc295836742"3.1DS18B20简介5HYPERLINK\l”_Toc295836743"3。1。1DS18B20封装与引脚5HYPERLINK\l”_Toc295836744”3.1.2DS18B20的简单性能53.3DS18B20的测温原理6HYPERLINK\l”_Toc295836747”3。3.1测温原理:63.3.2DS18B20的温度采集过程9HYPERLINK\l”_Toc295836749”第四章单片机接口设计10HYPERLINK\l”_Toc295836750"4。1设计原则104。2单片机引脚连接10HYPERLINK\l”_Toc295836752"4。2。1单片机引脚图10HYPERLINK\l”_Toc295836753"4.2。2串口引脚11第五章硬件电路设计12_Toc295836758"5。2.2程序组成16HYPERLINK\l”_Toc295836759”结束语20HYPERLINK\l”_Toc295836760"致谢21,外接电源供电DS18B20发送“1”计数器计数器斜率累加器减到0减法计数器预置低温度系数振荡器高温度系数振荡器计数比较器预置温度寄存器减到0图3。2测温原理内部装置3。3。2DS18B20的温度采集过程由于DS18B20单线通信功能是分时完成的,他有严格的时隙概念,因此读写时序很重要,系统对DS18B20的各种操作必须按协议进行。操作协议为:初始化DS18B20(发复位脉冲)→发ROM功能命令→发存储器操作命令→处理数据.温度的采集流程如图3。3所示.初始化初始化DS18B20跳过ROM匹配温度变换延时1S跳过ROM匹配读暂存器转换成显示码数码管显示图3.3DS18B20测温流程第四章单片机接口设计4。1设计原则DS18B20有2种供电方式,一种是直流电源,还有一种是寄生虫方式供电。采用电源供电方式,此时DS18B20的1脚接地,2脚作为信号线,3脚接电源。电源是利用直流稳压电源。当DS18B20处于写存储器操作和温度A/D变换操作时,总线上必须有强的上拉,上拉开启时间最大为10μs。采用寄生电源供电方式是VDD和GND端均接地。由于单线制只有一根线,因此发送接收口必须是三状态的。主机控制DS18B20完成温度转换必须经过3个步骤:初始化;ROM操作指令;存储器操作指令。4.2单片机引脚连接4。2。1单片机引脚图单片机引脚如图4。1所示。图4.1单片机引脚4。2.2串口引脚串口引脚的连接图如附录1.第五章硬件电路设计5。1主要硬件电路设计硬件电路主要包括:显示电路,DS18B20温度传感器检测电路,按键电路,晶振电路,二极管显示报警电路,电源电路。(1)显示电路显示电路采用了7段共阴数码管扫描电路,通过单片机的P0.0到P0.7八个端口接数码管的八个引脚,数码管的9号引脚接地.用来显示当前检测的温度值,精确度为0。1。如图5.1所示。节约了单片机的输出端口,便于程序的编写。本设计中还有一组数码管由P2.0到P2。7连接,除接口不同外其他一样,如图5.2。图5.1显示测量结果电路图图5.2显示限定温度电路(2)DS18B20温度传感器检测电路温度采集通过数字化的温度传感器DS18B20,通过QD接向单片机的P3。0口.DS18B20温度传感器电路如图5。3所示。图5。3温度传感器电路引脚图(3)按键电路按键电路如图5.4所示.由K2、K3、K4三个按键控制上、下限温度值。P3.1接口接K4按键.P3.2接口接入K3按键.P3.3接口接K2按键。1。K2温度上下限减少键:减少温度上下限的值。
2。K3温度上下限增加键:增加温度上下限的值.
3.K4温控开关键:进入温控的切换键.图5.4按键电路图(4)晶振控制电路晶振采用的是12MHZ的标准晶振。接入单片机的XTAL1、XTAL2.晶振控制电路如图5.5所示。图5.5晶振控制电路图(5)复位电路复位电路采用了人工复位的方式,按下按键K1使单片机复位。直接接到单片机的RESET引脚。复位电路如图5.6所示图5。6复位电路图(6)二极管显示报警电路二极管显示报警电路如图5.7所示.通过单片机的P3。4和P3.5两个端口送出,采用的是高电平驱动,使其发光发出警告。图5.7二极管显示电路(8)电源部分电源部分才用的是直流稳压电源,产生5V的稳定直流电压。电源设计部分如图5.8所示。图5。8电源部分电路5.2软件系统设计5。2.1软件系统设计一个应用系统要完成各项功能,首先必须有较完善的硬件作保证。同时还必须得到相应设计合理的软件的支持,尤其是微机应用高速发展的今天,许多由硬件完成的工作,都可通过软件编程而代替.甚至有些必须采用很复杂的硬件电路才能完成的工作,用软件编程有时会变得很简单,如数字滤波,信号处理等.因此充分利用其内部丰富的硬件资源和软件资源,采用与C51系列单片机相对应的51汇编语言和结构化程序设计方法进行软件编程.程序设计语言有三种:机器语言、汇编语言和高级语言。机器语言是机器唯一能“懂”的语言,用汇编语言或高级语言编写的程序(称为源程序)最终都必须翻译成机器语言的程序(成为目标程序),计算机才能“看懂",然后逐一执行。高级语言是面向问题和计算过程的语言,它可通过于各种不同的计算机,用户编程时不必仔细了解所用的计算机的具体性能与指令系统,而且语句的功能强,常常一个语句已相当于很多条计算机指令,于是用高级语言编制程序的速度比较快,也便于学习和交流,但是本系统却选用了汇编语言。原因在于,本系统是编制程序工作量不大、规模较小的单片机微控制系统,使用汇编语言可以不用像高级语言那样占用较多的存储空间,适合于存储容量较小的系统.同时,本系统对位处理要求很高,需要解决大量的逻辑控制问题。51指令系统的指令长度较短,它在存储空间和执行时间方面具有较高的效率,编成的程序占用内存单元少,执行也非常的快捷,与本系统的应用要求很适合。而且AT89C-51指令系统有丰富的位操作(或称位处理)指令,可以形成一个相当完整的位操作指令子集,这是AT89C-51指令系统主要的优点之一。对于要求反应灵敏与控制及时的工控、检测等实时控制系统以及要求体积小、系统小的许多“电脑化”产品,可以充分体现出汇编语言简明、整齐、执行时间短和易于使用的特点.本装置的软件包括主程序、读出温度子程序、复位应答子程序、写入子程序、以及有关DS18B20的程序(初始化子程序、写程序和读程序)。5.2.2程序组成系统程序主要包括主程序,读出温度子程序,写入子程序,门限调节子程序等。1)主程序主程序的主要功能是负责温度的实时显示、读出并处理DS18B20的测量的当前温度值,温度测量每1s进行一次。这样可以在一秒之内测量一次被测温度,其程序流程见图5.9所示.通过调用读温度子程序把存入内存储中的整数部分与小数部分分开存放在不同的两个单元中,然后通过调用显示子程序显示出来。图5.9主程序流程图2)读出温度子程序读出温度子程序的主要功能是读出RAM中的9字节,在读出时需进行CRC校验,校验有错时不进行温度数据的改写,程序流程图如图5。10所示。DS18B20的各个命令对时序的要求特别严格,所以必须按照所要求的时序才能达到预期的目的,同时,要注意读进来的是高位在后低位在前,共有12位数,小数4位,整数7位,还有一位符号位。DS18B20复位、应答子程序DS18B20复位、应答子程序跳过ROM匹配命令跳过ROM匹配命令写入子程序写入子程序温度转换命令温度转换命令写入子程序写入子程序显示子程序(延时)显示子程序(延时)DS18B20复位、应答子程序DS18B20复位、应答子程序跳过ROM匹配命令跳过ROM匹配命令写入子程序写入子程序读温度命令子程序读温度命令子程序终终止图5。10读出温度子程序3)写入子程序写入子程序的流程图如5.11所示。开始开始进位C清0进位C清0终止R2是否为0P3.0置0延时46US带进位右移延时12USP3.0清0终止R2是否为0P3.0置0延时46US带进位右移延时12USP3.0清0图5.11写入子程序4)门限调节子程序门限调节子程序流程如图5。12所示。图5。12门限调节电路结束语本文详细讲述了系统设计方案,并给出了相关程序流程。本设计应用性比较强,可以应用在仓库温度、大棚温度、机房温度、水池等的监控。另外,如果把本设计方案扩展为多点温度控制,加上上位机,则可以实现远程温度监控系统,将具有更大的应用价值。本文的创新点在于详细设计了基于单片机AT89C51的温度监控系统,设计程序已经。此系统可广泛用于温度在DS18B20测温范围之内的场合,有良好的应用前景。由于单片机的各种优越的特性,使得它的经济效益显的更加突出,有很好的实用性。附录附录1原理电路总设计图附录2源程序: FK1EQU24H;F(k)实测温度FKEQU25H;F(k)实测温度暂存RKEQU26H;R(k)给定温度SHI1EQU30H;实测温度十位SHI2EQU31H;实测温度个位SHI3EQU32H;实测温度小数位GAOEQU33H;给定温度十位ZHOEQU34H;给定温度个位DIEQU35H;给定温度小数位CNTEQU37H;按键消抖计数器LSBEQU50H;检测温度低8位MSBEQU51H;检测温度高8位K_INMBITP3.1;DI位设定温度按键K_INHBITP3。2;ZHO位设定温度按键KIBITP3.3;GAO位设定温度按键DQBITP3.0;DS18B20的温度输入口ORG0000H;主程序入口地址AJMPMAIN;跳转到主程序ORG000BH;T0中断入口地址ORG001BH;T1中断入口地址ORG0050HMAIN:MOVSP,#60H;堆栈指针初始化MOVGAO,#0;置设定值显示十位初值MOVZHO,#0;置设定值显示个位初值MOVDI,#0;置设定值显示小数位初值MOVCNT,#10;MOVTMOD,#11H;定时器T0、T1初始化(方式1)MOVTH0,#3CH;T0定时器定时常数MOVTL0,#0B0H;MOVTH1,#0FCH;T1定时器定时常数MOVTL1,#18H;SETBPT1;T1优先中断MOVIE,#8AH;中断使能SETBTR0;启动定时器T0SETBTR1;启动定时器T1LOOP:ACALLGETTMP;调用测温子程序ACALLBBLD;调用二十进制子程序ACALLTER;调用拆字子程序ACALLXIAOSHU;调用小数处理子程序ACALLDISP1;调用测得温度显示程序ACALLKEY;调用按键处理子程序ACALLIDTB;调用十二进制转换子程序ACALLCHK1;调用报警子程序ACALLDISP2;调用设定温度显示子程序AJMPLOOP;循环;*******测温子程序******GETTMP:ACALLRESET_PULSEACALLPRESENCEMOVA,#0CCHACALLWRITE_BYTE;发跳过ROM命令MOVA,#44HACALLWRITE_BYTE;发出温度转换命令JNBDQ,$ACALLRESET_PULSEACALLPRESENCEMOVA,#0CCH;发跳过ROM命令ACALLWRITE_BYTEMOVA,#0BEH;发读存储器命令ACALLWRITE_BYTEACALLREAD_BYTEMOVLSB,A;温度值低位字节送LSBACALLREAD_BYTEMOVMSB,A;温度值高位字节送MSBACALLRESET_PULSEACALLPRESENCEMOVA,MSBSWAPAANLA,#70HMOVFK,AMOVA,LSBSWAPAANLA,#0FHORLFK,AMOVFK1,FKRET;*****读DS18B20的程序*******READ_BYTE:MOVR6,#8READ1:CLRDQNOPNOPSETBDQNOPNOPNOPMOVR5,AMOVC,DQMOVA,R5MOVR7,#30DJNZR7,$RRCADJNZR6,READ1RETPRESENCE:JBDQ,$JNBDQ,$RETRESET_PULSE:CLRDQMOVR7,#250DJNZR7,$SETBDQMOVR7,#10DJNZR7,$RET;**********写DS18B20的程序*******WRITE_BYTE:MOVR6,#8WRITE:RRCAJCWRITE1CLRDQMOVR7,#30DJNZR7,$SETBDQNOPNOPNOPNOPDJNZR6,WRITERETWRITE1:CLRDQNOPNOPNOPNOPSETBDQMOVR7,#30DJNZR7,$DJNZR6,WRITERET;******二十进制转换子程序*****BBLD:CLRAMOVR2,AMOVR7,#8BBCD1:CLRCMOVA,FKRLCAMOVFK,AMOVA,R2ADDCA,R2DAAMOVR2,ADJNZR7,BBCD1RET;******拆字子程序*******TER:MOVA,R2ANLA,#0FHMOVSHI2,AMOVA,R2SWAPAANLA,#0FHMOVSHI1,ARET;*******小数部分处理子程序******XIAOSHU:CLRCMOVR3,#3MOVA,50HLOOP2:RRCADJNZR3,LOOP2ANLA,#01HCJNEA,#01H,XIAOSHU2MOVSHI3,#5RETXIAOSHU2:MOVSHI3,#0RET;******按键部分处理子程序*******KEY:MOVCNT,#80JBK_INM,KEY1ACALLDISP1ACALLDISP2ACALLDISP1ACALLDISP2JBK_INM,KEY1WAIT0:JBK_INM,KEY2ACALLDISP1ACALLDISP2DJNZCNT,WAIT0KEY2:MOVA,DIADDA,#5DAAMOVDI,ASUBBA,#09HJCKEY1MOVDI,#0KEY1:MOVCNT,#80JBK_INH,KEY4ACALLDISP1ACALLDISP2ACALLDISP1ACALLDISP2JBK_INH,KEY4WAIT1:JBK_INH,KEY3ACALLDISP1ACALLDISP2DJNZCNT,WAIT1KEY3:MOVA,ZHOADDA,#1DAAMOVZHO,ACJNEA,#10H,KEY4MOVZHO,#0KEY4:MOVCNT,#80JBKI,KEY_BACKACALLDISP1ACALLDISP2ACALLDISP1ACALLDISP2JBKI,KEY_BACKWAIT2:JBKI,KEY5ACALLDISP1ACALLDISP2DJNZCNT,WAIT2KEY5:MOVA,GAOADDA,#1DAAMOVGAO,ACJNEA,#10H,KEY_BACKMOVGAO,#0KEY_BACK:RET;******延时程序1******D0.6S:MOVR3,#64HDEL3:MOVR4,#384HDEL4:NOPNOPNOPDJNZR4,DEL4DJNZR3,DEL3RET;******实测温度显示部分子程序*******DISP1:MOVDPTR,#TABMOVA,SHI1MOVCA,@A+DPTRMOVP0,AMOVP1,#3FHCLRP1。0ACALLTMMOVA,SHI2MOVCA,@A+DPTRMOVP0,AMOVP1,#3FHSETBP0。7CLRP1。1ACALLTMMOVA,SHI3MOVCA,@A+DPTRMOVP0,AMOVP1,#3FHCLRP1。2ACALLTM;******实测温度显示部分子程序*******DISP2:MOVDPTR,#TABMOVA,GAOMOVCA,@A+DPTRMOVP2,AMOVP1,#3FHCLRP1.3ACALLTMMOVA,ZHOMOVCA,@A+DPTRMOVP2,AMOVP1,#3FHSETBP2.7CLRP1。4ACALLTMMOVA,DIMOVCA,@A+DPTRMOVP2,AMOVP1,#3FHCLRP1。5ACALLTMRETTAB:DB3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH;****显示延时子程序*******TM:MOVR1,#30TM1:MOVR2,#25TM2:DJNZR2,TM2DJNZR1,TM1RET;*******十二进制转换子程序*******IDTB:MOVR0,#33HMOVR2,#1MOVA,@R0MOV52H,ADITB1:MOVA,52HMOVB,#10MULABMOV52H,AMOVA,BINCR0MOVA,52HADDA,@R0MOV52H,AMOVRK,52HRET;*******设定温度越线报警子程序*****CHK1:MOVA,DICLRCSUBBA,#0MOVA,ZHOSUBBA,#0MOVA,GAOSUBBA,#4JCOUTBMOVA,DICLRCSUBBA,#5MOVA,ZHOSUBBA,#0MOVA,GAOSUBBA,#9JNCOUTAMOVA,#00HRETOUTA:MOVGAO,#9MOVZHO,#0MOVDI,#0CLRP3.4ACALLD0。6SSETBP3。4RETOUTB:MOVGAO,#4MOVZHO,#0MOVDI,#0CLRP3。4ACALLD0.6SSETBP3。4RETEND参考文献1.张友德主编《单片微型机原理,应用与实验》复旦大学出版社出版19932.何立民主编《单片机应用技术选编(1)》北京航空航天大学出版社20003.韦珑珅;杨荣松;基于DS18B20的单片机多点温度测量系统机械与电子4.赵娜;赵刚;于珍珠;郭守清;基于51单片机的温度测量系统,2007,(02)5.StevenF。Barrett,DanielJ。Pack。EmbeddedSystem[M].北京:电子工业出版社,20066.陈跃东.DS18B20集成温度传感器原理与应用[J]。安徽机电学院学报,20027.阎石.数字电子技术基础(第三版)[M].北京:高等教育出版社,19898.李朝青,单片机原理及接口技术(简明修订版)[M]。北京:北京航空航天大学出版社,19989.李广弟。单片机基础[M]。北京:北京航空航天大学出版社,199410.金伟正。单线数字温度传感器的原理与应用[J]。电子技术与应用,200011.李钢.1—Wire总线数字温度传感器DS18B20原理及应用.现代电子技术[J]南昌工程学院毕业设计(论文)成绩评定和评语姓名班级学号Ⅰ.毕业设计(论文)题目:Ⅱ。指导教师评语及评分评语:评分:指导教师:年月日Ⅲ。答辩委员会(小组)评语及评分评语:评分:总评成绩:答辩委员会(小组)负责人:年月
外文原文:
Design
of
the
Temperature
Control
System
Based
on
AT89C51
ABSTRACT
The
principle
and
functions
of
the
temperature
control
system
based
on
micro
controller
AT89C51
are
studied,
and
the
temperature
measurement
unit
consists
of
the
1—Wire
bus
digital
temperature
sensor
DS18B20。
The
system
can
be
expected
to
detect
the
preset
temperature,
display
time
and
save
monitoring
data。
An
alarm
will
be
given
by
system
if
the
temperature
exceeds
the
upper
and
lower
limit
value
of
the
temperature
which
can
be
set
discretionarily
and
then
automatic
control
is
achieved,
thus
the
temperature
is
achieved
monitoring
intelligently
within
a
certain
range.
Basing
on
principle
of
the
system,
it
is
easy
to
make
a
variety
of
other
non—linear
control
systems
so
long
as
the
software
design
is
reasonably
changed.
The
system
has
been
proved
to
be
accurate,
reliable
and
satisfied
through
field
practice.
KEYWORDS:
AT89C51;
micro
controller;
DS18B20;
temperature
1
INTRODUCTION
Temperature
is
a
very
important
parameter
in
human
life.
In
the
modern
society,
temperature
control
(TC)
is
not
only
used
in
industrial
production,
but
also
widely
used
in
other
fields.
With
the
improvement
of
the
life
quality,
we
can
find
the
TC
appliance
in
hotels,
factories
and
home
as
well.
And
the
trend
that
TC
will
better
serve
the
whole
society,
so
it
is
of
great
significance
to
measure
and
control
the
temperature.
Based
on
the
AT89C51
and
temperature
sensor
DS18B20,
this
system
controls
the
condition
temperature
intelligently。
The
temperature
can
be
set
discretionarily
within
a
certain
range。
The
system
can
show
the
time
on
LCD,
and
save
monitoring
data;
and
automatically
control
the
temperature
when
the
condition
temperature
exceeds
the
upper
and
lower
limit
value.
By
doing
so
it
is
to
keep
the
temperature
unchanged.
The
system
is
of
high
anti-jamming,
high
control
precision
and
flexible
design;
it
also
fits
the
rugged
environment。
It
is
mainly
used
in
people's
life
to
improve
the
quality
of
the
work
and
life。
It
is
also
versatile,
so
that
it
can
be
convenient
to
extend
the
use
of
the
system。
So
the
design
is
of
profound
importance.
The
general
design,
hardware
design
and
software
design
of
the
system
are
covered。
1.1
Introduction
The
8—bit
AT89C51
CHMOS
microcontrollers
are
designed
to
handle
high-speed
calculations
and
fast
input/output
operations.
MCS
51
microcontrollers
are
typically
used
for
high-speed
event
control
systems。
Commercial
applications
include
modems,
motor—control
systems,
printers,
photocopiers,
air
conditioner
control
systems,
disk
drives,
and
medical
instruments.
The
automotive
industry
use
MCS
51
microcontrollers
in
engine-control
systems,
airbags,
suspension
systems,
and
antilock
braking
systems
(ABS)。
The
AT89C51
is
especially
well
suited
to
applications
that
benefit
from
its
processing
speed
and
enhanced
on—chip
peripheral
functions
set,
such
as
automotive
power-train
control,
vehicle
dynamic
suspension,
antilock
braking,
and
stability
control
applications。
Because
of
these
critical
applications,
the
market
requires
a
reliable
cost-effective
controller
with
a
low
interrupt
latency
response,
ability
to
service
the
high
number
of
time
and
event
driven
integrated
peripherals
needed
in
real
time
applications,
and
a
CPU
with
above
average
processing
power
in
a
single
package。
The
financial
and
legal
risk
of
having
devices
that
operate
unpredictably
is
very
high.
Once
in
the
market,
particularly
in
mission
critical
applications
such
as
an
autopilot
or
anti-lock
braking
system,
mistakes
are
financially
prohibitive。
Redesign
costs
can
run
as
high
as
a
$500K,
much
more
if
the
fix
means
2
back
annotating
it
across
a
product
family
that
share
the
same
core
and/or
peripheral
design
flaw。
In
addition,
field
replacements
of
components
is
extremely
expensive,
as
the
devices
are
typically
sealed
in
modules
with
a
total
value
several
times
that
of
the
component。
To
mitigate
these
problems,
it
is
essential
that
comprehensive
testing
of
the
controllers
be
carried
out
at
both
the
component
level
and
system
level
under
worst
case
environmental
and
voltage
conditions.
This
complete
and
thorough
validation
necessitates
not
only
a
well—defined
process
but
also
a
proper
environment
and
tools
to
facilitate
and
execute
the
mission
successfully.
Intel
Chandler
Platform
Engineering
group
provides
post
silicon
system
validation
(SV)
of
various
micro-controllers
and
processors.
The
system
validation
process
can
be
broken
into
three
major
parts.
The
type
of
the
device
and
its
application
requirements
determine
which
types
of
testing
are
performed
on
the
device.
1.2
The
AT89C51
provides
the
following
standard
features
4Kbytes
of
Flash,
128
bytes
of
RAM,
32
I/O
lines,
two
16—bittimer/counters,
a
five
vector
two-level
interrupt
architecture,
a
full
duple
ser—ial
port,
on-chip
oscillator
and
clock
circuitry。
In
addition,
the
AT89C51
is
designed
with
static
logic
for
operation
down
to
zero
frequency
and
supports
two
software
selectable
power
saving
modes。
The
Idle
Mode
stops
the
CPU
while
allowing
the
RAM,
timer/counters,
serial
port
and
interrupt
sys
—tem
to
continue
functioning。
The
Power—down
Mode
savesthe
RAM
contents
but
freezes
the
oscil–lator
disabling
all
other
chip
functions
until
the
next
hardware
reset.
1.3Pin
Description
VCC
Supply
voltage。
GND
Ground。
Port
0:Port
0
is
an
8-bit
open—drain
bi-directional
I/O
port。
As
an
output
port,
each
pin
can
sink
eight
TTL
inputs.
When
1s
are
written
to
port
0
pins,
the
pins
can
be
used
as
high
impedance
inputs.
Port
0
may
also
be
configured
to
be
the
multiplexed
low
order
address/data
bus
during
accesses
to
external
program
and
data
memory.
In
this
mode
P0
has
internal
pull
ups。
Port
0
also
receives
the
code
bytes
during
Flash
programming,
and
outputs
the
code
bytes
during
program
verification.
External
pull
ups
are
required
during
program
verification.
Port
1:Port
1
is
an
8-bit
bi—directional
I/O
port
with
internal
pull
ups。
The
Port
1
output
buffers
can
sink/so
-urce
four
TTL
inputs。
When
1s
are
written
to
Port
1
pins
they
are
pulled
high
by
the
internal
pull
ups
and
can
be
used
as
inputs。
As
inputs,
Port
1
pins
that
are
externally
being
pulled
low
will
source
current
(IIL)
because
of
the
internal
pullups.
Port
1
also
receives
the
low—order
address
bytes
during
Flash
programming
and
verification。
Port
2:Port
2
is
an
8—bit
bi-directional
I/O
port
with
internal
pull
ups。
The
Port
2
output
buffers
can
sink/source
four
TTL
inputs.
When
1s
are
written
to
Port
2
pins
they
are
pulled
high
by
the
internal
pull
ups
and
can
be
used
as
inputs.
As
inputs,
Port
2
pins
that
are
externally
being
pulled
low
will
source
current
(IIL)
because
of
the
internal
pull
ups.
Port
2
emits
the
high-order
address
byte
during
fetches
from
external
program
memory
and
during
accesses
to
Port
2
pins
that
are
externally
being
pulled
low
will
source
current
(IIL)
because
of
the
internal
pull
ups。
Port
2
emits
the
high—order
address
byte
during
fetches
from
external
program
memory
and
during
accesses
to
external
data
memory
that
use
16-bit
addresses
(MOVX@DPTR)。
In
this
application,
it
uses
strong
internal
pull—ups
when
emitting
1s.
During
accesses
to
external
data
memory
that
use
8—bit
addresses
(MOVX
@
RI),
Port
2
emits
the
contents
of
the
P2
S
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