STC89C52处理芯片-毕业论文外文翻译

中文翻译

STC89C52处理芯片

电气工程的研究和解决方案中心（ceers）

艾哈迈德为吉.波特

首要性能：

与MCS-51单片机产物兼容、8K字节在系统可编程视频存储器、1000次擦拭周期，全静态操作：0Hz~33Hz、三级加密程序存储器，32个可编程I/O接口线、三个16位定时器（计数器），八个中断源、低功能耗空闲和掉电模式、掉电后间断可唤醒，看门狗定时器、双数值指针，掉电标示符。

关键词：单片机，UART串行通道，掉电标示符等

前言

可以说，二十世纪跨越了三个“点”的时代，即电气时代，电子时代和现已进入的电脑时代。不过，这种电脑，通常指的是个人计算机，简称PC机。还有就是把智能赋予各种机械的单片机（亦称微控制器）。顾名思义，这种计算机的最小系统只用了一片集成电路，即可进行简单的运算可控制。因为它体积小，通常都是藏在被控机械的内部里面。它在整个装置中，起着有如人类头脑的作用，他出了毛病，整个装置就会瘫痪。现在，单片机的种类和适用领域已经十分广泛，如智能仪表、实施工控、通讯设备、导航系统、家用电器等。各种产品一旦用上了单片机，就你能起到产品升级换代的功效，常在产品名称前冠以形容词——“智能型”，如智能洗衣机等。接下来就是关于国产STC89C52单片机的一些基本参数。

功能特性描述:

STC89C52单片机是一种低功耗、高性能CMOS8位微控制器，具有8K在系统可编程视频播放存贮器使用高密度非易失性存储器技术制造，与工业80C51 产物指令和引脚完全兼容。片上反射速度允许程序存储器在系统可编程，也适用于常规的程序编写器。在其单芯片上，拥有灵敏小巧的八位中央处理器和在线系统可编程反射，这些使用上STC89C52微控制器为众多嵌入式的控制应用系统提供高度矫捷的、更加有用的解决方案。STC89C52微控制器具有以下的标准功效：8K字节的反射速度，256字节的随机存取储存器，32位I/O串口线，看门狗定时器，2个数值指针，三个16

为定时器、计数器，一个6向量2级间断结构，片内晶振及钟表电路。另外，STC89C52可降至0HZ静态逻辑操作，支持两种软件可选择节电模式、间断继续工作。空闲模式下，CPU停止工作，允许RAM、定时器/计数器、串口、间断继续工作。掉电保护体式格局下，RAM内容被生成，振动器被冻结，单片机一切的工作停止，直到下一个间断或者硬件复位为止。8位微型控制器8K字节在系统中可编程FlashSTC89C52.。

P0口：P0口是一个8位漏极开路的双向I/O口。作为输出口，每位能驱动8个TTL逻辑电平，对于P0端口写“1”时，引脚用作高阻抗输入。

当访问外部程序和数值存储器时，P0口也被作为低八位/数值复用。在这种模式下，P0具有内部上拉电阻。

在Flash编程时，P0口也用来接收指令字节；在程序校验时，输出指令字节。在程序校验时，需要外部上拉电阻。

P1口：P1口是一个具有内部上拉电阻的八位双向I/O 口，P1输出缓冲器驱动四个TTL逻辑电平。对于P1端口写“1”时，内部上拉电阻把端口拉高，此时可以作为输入口使用。作为输入使用时，被外部拉低的引脚由于内部电阻的原因，将输出电流（IIL）。

此外，P1.0和P1.2分别作为定时器/计数器2的外部计数输出（P1.0、T2）和定时器、计数器2的触发输入（P1.1、T2EX），具体如下所示。在Flash编程和校验时，P1口吸收低8位地址字节。

引脚号第二功效：

P1.0 T2（定时器、计数器T2的外部计数输入），钟表输出。）

P1.1 T2EX（定时器，计数器T2的捕捉、重载触发信号和方向控制。）

P1.5 MOSI（在线系统编程用。）

P1.6MISO（在线系统编程用。）

P1.7SCK（在线系统编程用。）

P2口：P2口是一个具有内部上拉电阻的8位双向I/O口，P2输出缓冲器能驱动四个TTL逻辑电平。对于P2端口写“1”时，内部上拉电阻把端口拉高，此时可以作为输入口使用。

在访问外部程序存储器或者用16位地址读取外部数值存储器（例如执行

MOVX@DPTR）时，P2口送出高八位地址。在这种应用中，P2口使用很强的内部上拉发送“1”。在使用8位地址（如MOVX@RI）访问外部数值存储器时，P2口输出P2锁存器的内容。在Flash编程和校验时，P2口也接收高8位地址字节和一些控制信号。

P3口：P3口是一个具有内部上拉电阻的8位双向I/O，P2输出缓冲器能驱动四个TTL逻辑电平，对于P3端口写“1”时，内部上拉电阻把端口拉高，此时可以作为输入口使用。。P3口亦作为STC89C52特殊功效（第二功效）使用，如下表所示，早flash编程和校验时，P3口也接收一些控制信号。

P3.0 RXD（串行输入口。）

P3.1 TXD（串行输出口。）

P3.2 INTO（外间断0）

P3.3 INTI（外间断1）

P3.4 TO（定时、计数器0）

P3.5 T1（定时、计数器1）

P3.6 WR（外部数值存储器写选通）

P3.7 RD（外部数值存储器读选通）

此外，P3口还吸收一些用于Flash闪存编程和程序校验的控制信号。

RST——复位输入：当振动器工作时，RST引脚出现两个机器周期以上高电平将使单片机复位。

ALE/ PROG——当访问外部程序存储器或数字存储器，ALE（地址锁存允许）输出脉冲用于锁存地址的低八字节。通常情况下，ALE以时钟频率的1 / 6输出的脉冲信号与固定，因此它可用于输出时钟频率或者定时目的。值得注意的是：每当访问外部存储器，将跳过一个ALE脉冲数值。

对于Flash存储器编程期间，该引脚还用于输入编程脉冲（PROG）。

如有必要，可通过对于特殊功效寄存器（SFR）区中的8EH单位的D0位置位，可禁止ALE操作，只有一条MOVX和MOVC指令才能将ALE激活。此外，该引脚会被微弱拉高，单片机执行外部程序时，应设置ALE禁止位无效。

PSEN——程序储存允许（PSEN）输出是外部程序存储器的读选通信号，当STC89C52由外部程序存储器取指令（或者数值）时，每一个机器周期两次PSEN有用，即输出两个脉冲，在此期间，当访问外部数值存储器，将跳过两次PSEN信号。

EA、VPP——外部访问允许，欲使CPU仅访问外部程序存储器（地址为

0000H-FFFFH），EA端必须保持低电平（接地）。须注意的是：如果加密位LB1被编程，复位时内部会锁存EA端状态。

如EA端为高电平（接Vcc端），CPU则执行内部程序存储的指令。

Flash存储器编程时，该引脚加上+12伏的编程允许电源VPP，当然这必须是该部件是使用12伏编程电压VPP。

看门狗定时器：WDT 是一种需要软件控制的复位方式。WDT 由13位计数器和特殊功能寄存器中的看门狗定时器复位存储器（WDTRST)构成。WDT在默认情况下无法工作；为了激活WDT，用户必须往WDTRST寄存器（地址：0A6H）中依次写入01EH 和0E1H。当激活WDT 后，晶振工作，WDT在每个机器周期都会增加。WDT计时周期依赖于外部时钟频率，除了复位（硬件复位或者WDT溢出复位），没有办法停止WDT工作。

STC89C52 单片机有一个用于构成内部振荡器的反相放大器，XTAL1和XTAL2 分别是放大器的输入、输出端。石英晶体和陶瓷谐振器都可以用来一起构成自己振荡器。接外部时钟源驱动器件的话，XTAL2可以不接，只接入XTAL1。由于外部时钟

信号经过二分频触发后作为外部时钟电路输出的，所以对外部时钟信号的占空比没有其他要求，最长低电平持续时间和最少高电平持续时间等还是要符合要求的。

空闲模式：在空闲模式下，CPU处于睡眠状态，而所有片上外部设备保持激活状态。这种状态可以通过软件产生。在这种状态下，片上RAM和特殊功能寄存器的内容保持不变。空闲模式可以被任意一个中断或者硬件复位终止。由硬件复位终止空闲模式只需要两个机器周期有效复位信号，在这种情况下，片上硬件禁止访问内部RAM，而可以访问端口引脚。空闲模式被硬件复位终止后，为防止预想不到的写端口，激活空闲模式的那一条指令的下一条指令不应该是写端口或外部存储器。

总结

单片机内部也用和电脑功能类似的模块，比如CPU，内存，并行总线，还有和硬盘作用相同的存储器件，不同的是它的这些部件性能都相对我们的家用电脑弱很多，不过价钱也是低的，一般不超过10元即可用它来做一些控制电器一类不是很复杂的工作也足够了。我们现在用的全自动滚筒洗衣机、排烟罩、VCD等等的家店里面都可以看到他的身影！它主要是作为控制部分的核心部件。

它是一种在线式实时控制计算机，在线式就是现场控制，需要的是有较强的抗干扰能力，较低的成本，这也是和离线式计算机（比如家用电脑）的主要区别。

STC89C52 processing chip

Center for Electrical Engineering Research and Solution(CEERS)

Ahmad Dahlan JI. Prot

Prime features：

With MCS-51 SCM product compatibility，8K bytes in the system programmable Flash memory，1000 times CaXie cycle，the static operation:0Hz~33Hz,triple encryption program memory,32programmed I/O port, three 16 timer/counter, the eight uninterrupted dual-career UART serial passage, low power consumption ,leisure and fall after electric power made can be awakened and continuous watchdog timer and double-number pointer,power identifier.

Keyword: SCM(Single-chip microcontroller，UART serial passage，power identifier.···) Introductive

Can be said that the twentieth century across the three “power” era, that is ,the age of electricity, the electronic age and has entered into the computer age .However, this computer, usually refers to the personal computer, referred to as PC .It consists of the host, keyboard, monitor and other components, Another type of computer, most people do not know how. This computer is to give all kinds of intelligent machines single chip(also known as micro-controller).As the name suggests, this computer system took only a minimal integrated circuit, can be a simple operation and control. Because it is small, usually hidden in the charged mechanical “stomach” in, It is in the device, like the human brain plays a role, it goes wrong, the whole plant was paralyzed. Now this microcontroller has a very broad field of use, such as smart meters, real-time industrial control, communications equipment, navigation systems, and household appliances. Once all kinds of products were using SCM, can serve to upgrade the effectiveness of products, often in the product name preceded name preceded by the adjective “intelligent” such as intelligent washing machines.

STC89C52 Introduction

Efficacy:characteristics

STC89C52 is one kind of low power consumption,high COMOSS bit micro-controller,8K in system programmable Flash memory,Use high-density nonvolatile storage technology,and industrial 80C51 product instruction and pin fully compatible.The Flash memory chips allows programs in the system,also suitable for programmable conventional programming.In a single chip,have clever 8 bits CPU and online system programmable Flash,increase STC89C52 fro many embedded control system to provide high vigorous application and useful solutions STC89C52 has following standard efficacy: SK byte Flash RAM,256 bytes,32 I/O port,the watching timer,two,three pointer numerical 16 timer/counter,a 6 vector level 2 continuous structure,the serial port,working within crystals and horological circuit.In addition,0Hz STC89C52 can drop to the static logic operation,support two software can choose power saving mode.Idle mode,the CPU to stop working,and allows the RAM ,timer/counter,serial,continuous to work.Protection asana pattern,RAM content is survival,vibrators frozen,SCM,until all the work under a continuous

or hardware reset,8-bit microcontrollers 8K bytes in the system programmable Flash STC89C52 devices.

Mouth:PO PO mouth is a two-way open drain I/O.As export,each can drive eight TTL. logic level.For PO port to write “1”,foot as the high impedance input

When access to external programs and numerical memory,also known as low PO mouth eight address/numerical reuse.In this mode,with the intern a1 PO resistor.

In the flash when programming,also used for PO mouth;adsorb instruction bytes.In the process,the output command bute calibration.When the program requires external,calibration on pull-up resistors.

Mouth:P1 mouth P1 is an internal resistance of the eight two-way I/O buffers can drive,P1 output four TTL logic level.To write “1”P1 port,the internal resistance to port,can push as input mouth.When used as input external and internal foot because of low resistance,will output current(IIL).

In addition,P1.0 and P1.2 respectively timer/counter 2 external counting input(P1.0/T2) and when the trigger editor/counter P1.1input(2),specific T2EX/are shown below.In programming and calibration,flash P1 mouth adsorb eight address low byte.

Efficacy:the foot.

P1.0 T2(timer/counter T2 external counting input),clock output.

P1.1 T2EX(timer/counter T2 capture/overloaded triggered signals and direction control);

P1.5 MOSI(with) online system programming;

P1.6 MISO(with) online system programming;

P1.7 SCK(with) online system programming;

Mouth:P2 P2mouth is an internal resistance of the eight two-way I/O buffers and P2 output can driver four TTL logic level.To write “1”P2 port,the internal resistance to port,can push as input mouth.When used as input,external and internal foot because of low resistance,will output current(IIL).

In the external program memory access or use 16bit external numercial memory address read(for example MOVX execution DPTR@),P2 mouth send out high 8 address.In using 8-bit address(such as MOVX @ RI) access to external numerical memory,P2 mouth output P2 latches content.In programming and calibration,flash P2 mouth also absorb high eight address byte and some control signal.

P3:a P3 mouth on the inside of the eight two-way pull-up resistors I/O buffers can drive,p2 output four TTL logic level.For P3 port to write “1”,the internal resistance to port,can push an input mouth.When used as input,external and internal foot because of low resistance,will output current(IIL).P3 mouth AT89S52 special functions(also as the second efficacy),are shown below.In programming and calibration,flash also absorb some P3 mouth control signals.

Port pin second efficacy:

P3.0 RXD(serial input),

P3.1 TXD(serial export),

P3.2 INTO the discontinuous(0),

P3.3 INT1(1) the discontinuous(0),

P3.4 (timer/counter TO 0),

P3.5 T1(1) timer/counter,

P3.6 WR(external numerical memory write for),

P3.7 RD( external numerical memory read for),

In addition,also absorb some used in mp3 mouth FLASH memory programming and calibration of program control signals.

RST,reset input:when the vibrator,RST pin appeared two machine cycle above high level will be reset the chip.

ALE/PROG-when access to external program memory or numerical memory,ALE (address latch allow) output pulses are used to latch address of low eight bytes.Normally,ALE with clock frequencies are 1/6 output pulse signal with fixed,so it can be used for the purpose or output clocks,Timing Those who want an attention is:whenever access to external numerical memory will skip a ALE pulse.

For FLASH memory programming,this pin is used for input programming pulse(.)PROG

If necessary,but through special effect to the zone registers(SFR)8EH D0 position,the unit can be banned ALE operations.This position is a bit,MOVX and MOVC instructions will be activated.ALE-In addition,the foot will be weak ,execute external program MCU hign should be banned,a void. Set ALE.

PSEN-program storage PSEN allowed (output is outside of the program memory read,choose communication by external program memory when taking AT89C52 instruction(or),each machine cycle PSEN twice,two pulse output is useful,during this period,when access to external numerical memory,will skip PSEN twice.

EA/VPP-external access permission,to make the CPU only access to external program memory (address for 0000H-FFFFH),EA end must remain low level(ground).Should notice is:if a LBI is encrypted,reset when programming will latch EA end.

As for the high level of the EA (VCCS),the CPU is the implementation of the program memory internal instructions.

FLASH memory when programming ,this pin plus+12V programming allow power Vpp,of course,that is the part is used to Vpp voltage 12V programming.

Watch Timer(One-time Enabled with Reset-out):The WDT is intended as a recovery method in situation where the CPU may be subjected to software upset.The WDT consist of a 14-bit counter and the watchdog Timer Reset(WDTRST)SFR.The WDT is defaulted to

disable from exiting reset. To enable the WDT, a user must write 01EH in sequence to the WDTRST register(SFR location 0A6H).When the WDT is enabled, it well increment every machine cycle while the oscillator is running. The WDT timeout period is dependent on the external clock frequency. There is no way to disable the WDT expect through reset(either hardware reset or WDT overflow reset).When WDT over-flow,it will drive an output RESET HIGH pulse at the RET pin.

Oscillator Characteristic:XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier that can be configured for use as an on-chip oscillator .Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven.there are no requirements on the duty cycle of the external clock signal, since the input to the internal clock-ing circuitry is through a divide-by-two flip-flop, by minimum voltage high and low time specifications must be observed.

Idle Mode:In idle mode ,the CPU puts itself to sleep while all the on-chip peripherals remain active.The mode is invoked by software. The content of the on-chip RAM and all the special function regis-ters remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. Note that when idle mode is terminated by a hardware reset, the device normally resumes program execution from where it left off,up to two machine cycle before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event,but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when idle mode is terminated by a reset, the instruction following the one that invokes idle mode should not write to a port pin or to external memory.

Conclusions

MCU and the computer use is also similar to the module ,such as CPU ,memory, parallel bus, as well as the role and the same hard disk memory, is it different from the performance of these components are relatively weak in our home computer a lot, but the price is ow,there is generally no more than 10 yuan…..san use it to make some control for a class of electrical work is not very complex is sufficient. We are using automatic drum washing machines, smoking hood, VCD and so on inside the home appliances can see it’s shadow! It is mainly as part of the core component of the control.

It is an online real-time control computer, control-line is that the scene is needed is a stronger anti-jamming ability, low cost, and this is, and off-line computer(such as home PC).the main difference.