英语翻译或者稳压控制系统方面,单片机介绍方面,AC/DC转换,A/D转换方面,双向可控硅方面都行,

英语翻译或者稳压控制系统方面,单片机介绍方面,AC/DC转换,A/D转换方面,双向可控硅方面都行,
英语翻译
或者稳压控制系统方面,单片机介绍方面,AC/DC转换,A/D转换方面,双向可控硅方面都行,

英语翻译或者稳压控制系统方面,单片机介绍方面,AC/DC转换,A/D转换方面,双向可控硅方面都行,
整个PEROM阵列和三个锁定位的电擦除可通过正确的控制信号组合,并保持ALE管脚处于低电平10ms 来完成.在芯片擦操作中,代码阵列全被写“1”且在任何非空存储字节被重复编程以前,该操作必须被执行.
此外,AT89C51设有稳态逻辑,可以在低到零频率的条件下静态逻辑,支持两种软件可选的掉电模式.在闲置模式下,CPU停止工作.但RAM,定时器,计数器,串口和中断系统仍在工作.在掉电模式下,保存RAM的内容并且冻结振荡器,禁止所用其他芯片功能,直到下一个硬件复位为止.
串口通讯
单片机的结构和特殊寄存器,这是你编写软件的关键.至于串口通信需要用到那些特殊功能寄存器呢,它们是SCON,TCON,TMOD,SCON等,各代表什么含义呢?
SBUF 数据缓冲寄存器这是一个可以直接寻址的串行口专用寄存器.有朋友这样问起过“为何在串行口收发中,都只是使用到同一个寄存器SBUF?而不是收发各用一个寄存器.”实际上SBUF 包含了两个独立的寄存器,一个是发送寄存,另一个是接收寄存器,但它们都共同使用同一个寻址地址－99H.CPU 在读SBUF 时会指到接收寄存器,在写时会指到发送寄存器,而且接收寄存器是双缓冲寄存器,这样可以避免接收中断没有及时的被响应,数据没有被取走,下一帧数据已到来,而造成的数据重叠问题.发送器则不需要用到双缓冲,一般情况下我们在写发送程序时也不必用到发送中断去外理发送数据.操作SBUF寄存器的方法则很简单,只要把这个99H 地址用关键字sfr定义为一个变量就可以对其进行读写操作了,如sfr SBUF = 0x99;当然你也可以用其它的名称.通常在标准的reg51.h 或at89x51.h 等头文件中已对其做了定义,只要用#include 引用就可以了.
SCON 串行口控制寄存器通常在芯片或设备中为了监视或控制接口状态,都会引用到接口控制寄存器.SCON 就是51 芯片的串行口控制寄存器.它的寻址地址是98H,是一个可以位寻址的寄存器,作用就是监视和控制51 芯片串行口的工作状态.51 芯片的串口可以工作在几个不同的工作模式下,其工作模式的设置就是使用SCON 寄存器.它的各个位的具体定义如下：
SM0 SM1 SM2 REN TB8 RB8 TI RI
SM0、SM1 为串行口工作模式设置位,这样两位可以对应进行四种模式的设置.串行口工作模式设置.
SM0 SM1 模式 功能 波特率
0 0 0 同步移位寄存器 fosc/12
0 1 1 8位UART 可变
1 0 2 9位UART fosc/32 或fosc/64
1 1 3 9位UART 可变
在这里只说明最常用的模式1,其它的模式也就一一略过,有兴趣的朋友可以找相关的硬件资料查看.表中的fosc 代表振荡器的频率,也就是晶振的频率.UART 为(Universal Asynchronous Receiver）的英文缩写.
SM2 在模式2、模式3 中为多处理机通信使能位.在模式0 中要求该位为0.
REM 为允许接收位,REM 置1 时串口允许接收,置0 时禁止接收.REM 是由软件置位或清零.如果在一个电路中接收和发送引脚P3.0,P3.1 都和上位机相连,在软件上有串口中断处理程序,当要求在处理某个子程序时不允许串口被上位机来的控制字符产生中断,那么可以在这个子程序的开始处加入REM=0 来禁止接收,在子程序结束处加入REM=1 再次打开串口接收.大家也可以用上面的实际源码加入REM=0 来进行实验.
TB8 发送数据位8,在模式2 和3 是要发送的第9 位.该位可以用软件根据需要置位或清除,通常这位在通信协议中做奇偶位,在多处理机通信中这一位则用于表示是地址帧还是数据帧.
RB8 接收数据位8,在模式2 和3 是已接收数据的第9 位.该位可能是奇偶位,地址/数据标识位.在模式0 中,RB8 为保留位没有被使用.在模式1 中,当SM2=0,RB8 是已接收数据的停止位.
TI 发送中断标识位.在模式0,发送完第8 位数据时,由硬件置位.其它模式中则是在发送停止位之初,由硬件置位.TI 置位后,申请中断,CPU 响应中断后,发送下一帧数据.在任何模式下,TI 都必须由软件来清除,也就是说在数据写入到SBUF 后,硬件发送数据,中断响应（如中断打开）,这时TI=1,表明发送已完成,TI 不会由硬件清除,所以这时必须用软件对其清零.
RI 接收中断标识位.在模式0,接收第8 位结束时,由硬件置位.其它模式中则是在接收停止位的半中间,由硬件置位.RI=1,申请中断,要求CPU 取走数据.但在模式1 中,SM2=1时,当未收到有效的停止位,则不会对RI 置位.同样RI 也必须要靠软件清除.常用的串口模式1 是传输10 个位的,1 位起始位为0,8 位数据位,低位在先,1 位停止位为1.它的波特率是可变的,其速率是取决于定时器1 或定时器2 的定时值（溢出速率）.AT89C51 和AT89C2051 等51 系列芯片只有两个定时器,定时器0 和定时器1,而定时器2是89C52 系列芯片才有的.
波特率在使用串口做通讯时,一个很重要的参数就是波特率,只有上下位机的波特率一样时才可以进行正常通讯.波特率是指串行端口每秒内可以传输的波特位数.有一些初学的朋友认为波特率是指每秒传输的字节数,如标准9600 会被误认为每秒种可以传送9600个字节,而实际上它是指每秒可以传送9600 个二进位,而一个字节要8 个二进位,如用串口模式1 来传输那么加上起始位和停止位,每个数据字节就要占用10 个二进位,9600 波特率用模式1 传输时,每秒传输的字节数是9600÷10＝960 字节.51 芯片的串口工作模式0的波特率是固定的,为fosc/12,以一个12M 的晶振来计算,那么它的波特率可以达到1M.模式2 的波特率是固定在fosc/64 或fosc/32,具体用那一种就取决于PCON 寄存器中的SMOD位,如SMOD 为0,波特率为focs/64,SMOD 为1,波特率为focs/32.模式1 和模式3 的波特率是可变的,取决于定时器1 或2（52 芯片）的溢出速率.那么我们怎么去计算这两个模
式的波特率设置时相关的寄存器的值呢?可以用以下的公式去计算.
波特率＝（2SMOD÷32）×定时器1 溢出速率
上式中如设置了PCON 寄存器中的SMOD 位为1 时就可以把波特率提升2 倍.通常会使用定时器1 工作在定时器工作模式2 下,这时定时值中的TL1 做为计数,TH1 做为自动重装值 ,这个定时模式下,定时器溢出后,TH1 的值会自动装载到TL1,再次开始计数,这样可以不用软件去干预,使得定时更准确.在这个定时模式2 下定时器1 溢出速率的计算公式如下：
溢出速率＝（计数速率）/(256－TH1)
上式中的“计数速率”与所使用的晶体振荡器频率有关,在51 芯片中定时器启动后会在每一个机器周期使定时寄存器TH 的值增加一,一个机器周期等于十二个振荡周期,所以可以得知51 芯片的计数速率为晶体振荡器频率的1/12,一个12M 的晶振用在51 芯片上,那么51 的计数速率就为1M.通常用11.0592M 晶体是为了得到标准的无误差的波特率,那么为何呢?计算一下就知道了.如我们要得到9600 的波特率,晶振为11.0592M 和12M,定时器1 为模式2,SMOD 设为1,分别看看那所要求的TH1 为何值.代入公式：
11.0592M
9600＝(2÷32)×((11.0592M/12)/(256-TH1))
TH1＝250
12M
9600＝(2÷32)×((12M/12)/(256-TH1))
TH1≈249.49
上面的计算可以看出使用12M 晶体的时候计算出来的TH1 不为整数,而TH1 的值只能取整数,这样它就会有一定的误差存在不能产生精确的9600 波特率.当然一定的误差是可以在使用中被接受的,就算使用11.0592M 的晶体振荡器也会因晶体本身所存在的误差使波特率产生误差,但晶体本身的误差对波特率的影响是十分之小的,可以忽略不计.
The whole PEROM array with three electricities which target wipe in addition to combining through a correct control signal, and keep an ALE pin to be placed in low to give or get an electric shock an even 10 mses to complete.Wipe in the chip in operation, the all of code array are write"1" and at any not- empty saving word stanza drive repeated plait distance before, that operation had to be carry out.
In addition, the AT89 C51 establishes steady state logic, can at low get to the condition of zero frequencies under the static state logic, support two kinds of softwares can choose of drop an electricity mode.Under the idle mode, the CPU stop work.But RAM, in fixed time machine, count a machine, string and break off system still at the work.While drop the electricity mode, contents and congelation which keep RAM flap to concuss a machine, forbid other chip functions use, until the next hardware reset.
String communication
Single slice the structure of the machine with special deposit a machine, this be the key that you write software.As for does the string correspondence need to use to those special functions to deposit a machine, they are a SCON, TCON, TMOD, SCON etc., each representative what meaning?
SBUF data buffer's depositting a machine this is a string that can directly look for an address line's appropriation to deposit a machine.Had a friend to once start to ask so"why in the string the line receive and dispatch, all just use to same to deposit machine SBUF?But not is receive and dispatch each deposit a machine with 1."Actually the SBUF included deposit of two independence machine, 1 sends out to deposit, the another receives to deposit a machine, but they all together use same to look for an address address － 99 Hs.The CPU will point to receive to deposit a machine while read SBUF, while write will point to send out to deposit a machine, and receive to deposit a machine is a pair of buffer to deposit a machine, so can avoid receive to break off have no in time of is respond to, the data took away, next data already arrival, but result in of data layer after layer problem.Send out the machine then doesn't need to use a double a buffer and under the general circumstance we need not use to send out to break off, either to send a data to the outside haircut while writing to send out procedure.Operate then the method that the SBUF deposits a machine is easy, as long as use the key word sfr to this 99 H address the definition change to measure for 1 as to it's can carry on to read and write to operate, like sfr SBUF=0 xes 99;Certainly you can also use other names.As to it's usually have already done definition in head documents such as the reg 51. hs or the at 89 xes 51. h etc. of standard, as long as use#include quote from all right.
The SCON string line control deposits a machine usually to connect a people's appearance for the sake of the surveillance or the control in the chip or the equipments, will quote from to connect a people's control to deposit a machine.SCON be the string of 51 chips line the control deposit a machine.Its looking for an address address is a 98 Hs, is a can look for an address by of deposit a machine, function be surveillance and control 51 in line of work appearance.The string of 51 chips can work under a few different work modes and the constitution of its work mode is to use SCON to deposit a machine.It of the concrete definition of each as follows:
SM0 SM1 SM2 REN TB8 RB8 TI RI
The SM0, SM1 is the work mode of in a string of line constitution, so 2 can be to the constitution that should carry on four kinds of modes.String the line work mode establish.
The SM0 SM1 mode function wave especially rate
000 synchronously move to deposit the machine fosc/12
0 one one 8 UARTs are variable
One 029 UART fosc/32s or fosc/64
One one 39 UARTs are variable
At my mode with the most in common use elucidation 1, other modes also skip one by one and the friend who has interest can seek related hardware data to look into.The fosc representative in the form flaps frequency of concuss the machine, be also crystal flap of frequency.UART is(the Receiver of the Universal Asynchronous) of English abbreviation.
The SM2 is in the mode 2, the mode 3 for handle machine correspondence more to make an ability.Request that to 0 in the mode 0.
In order to allow to receive REM, the REM places 1:00 string to allow to receive and place to forbid to receive at 0:00.The REM is placed by the software or pure zero.If receive and send out to lead the feet P3.0 in an electric circuit, the P3.1s all connect with each other with place of honor machine, there is a string of on the software breaking off processing procedure, be request disallowing a string of while being handle some statures procedure was come by the place of honor machine of control character list to produce interruption, so can join REM in the beginning of this statures procedure=0 to forbid to receive, join REM at the sub- procedure be over=1 again open a string of to receive.Everyone can also join REM with the actual source code of top=0 to start experiment.
The TB8 sends out a data 8, in the mode 2 with 3 want to send out of the 9th.That can use software according to need to place or clearance, usually this is located on to do in the correspondence agreement strange accidentally, this is then used for mean in handle machine correspondence more is the address still a data.
The RB8 receives a data 8, in the mode 2 with 3 is the 9th which has already received a data.That may be strange accidentally, the address/data marking.In the mode 0, the RB8 wasn't use for the reservation.Be SM 2= in the mode 10, the RB8 is the stop which has already received a data.
The TI sends out to break off a marking.In the mode 0, finish send out the 8th data, is placed by the hardware.Then being send out the beginning of stop in other modes is placed by the hardware.After TI places, the application break off and the CPU after respond to the interruption sends out next data.Under any mode, the TIs all have to be come to clearance by the software, be also say after the data write in to the SBUF, the hardware sends out a data, the interruption respond to(if the interruption open), at this time TI=1, express to send out to have already complete, TI can't from hardware clearance, so have to use software at this time as to it's pure zero.
The RI receives to break off a marking.In the mode 0, receive the 8th be over, is placed by the hardware.Then being receive the midway of stop in other modes is placed by the hardware.RI=1, the application break off and request CPU to take away a data.But in the mode 1, SM 2=1:00, be receive valid of stop, then will not place to the RI.The same RI has to also want to depend software clearance.In common use string mode 1 deliver 10, a start is 0,8 data, low Be located on first, a stop is 1.It of wave especially the rate be variable, its velocity is to be decided by in fixed time a machine 1 or in fixed time machine 2 of in fixed time be worth.(overflow velocity)51 series chips such as the AT89 C51 and the AT89 C2051 etc. only have 2 in fixed time a machine, in fixed time machine 0 with in fixed time machine 1, but in fixed time machine 2 is what the 89 C52 series chip just has.
Wave especially rate at usage string do communication, a very important parameter be wave especially rate, only up and down the wave of the machine especially the similar hour of rate just can carry on normal communication.Wave especially the rate is the wave that can deliver inside port in a string line each one number especially.The friend who has some beginners think wave especially the rate mean the word stanza that each one deliver number, is mistaken for each one to grow and can deliver 9600 word stanzas such as standard 9600 meetings, but actually it means each one can deliver 9600 binary systems, but a word stanza want 8 binary systems, if use a string of mode 1 to deliver to so plus a start and stop, the piece will take up 10 binary systems according to the word stanza each time, 9600 especially the rate use mode 1 deliver, each one deliver of word stanza number is 9600 ÷s 10= be 960 word stanzas.The string of 51 chips work mode 0 waves especially the rate be fixed, is a fosc/12, with a 12 Ms of crystal flap to compute, so it of wave especially the rate can attain 1 M.Mode 2 waves especially the rate be fixed in the fosc/64 or the fosc/32 and concretely use that kind of be decided by PCON to deposit the SMOD in the machine, such as SMOD is 0, wave especially rate is focs/64, SMOD is 1, wave especially rate is focs/32.Mode 1 with mode 3 waves especially the rate be variable and be decided by in fixed time a machine is 1 or 2(52 chips) spillage velocities.So how do we go to compute these two molds
The wave of type especially the rate establish relatedly deposit the value of machine?Can compute with the following formula.
Wave especially rate=(2 SMOD ÷ 32)× in fixed time machine 1 overflow velocity
Last type in if established PCON to deposit the SMOD in the machine as 1:00 can wave especially the rate promote 200%.Usually use in fixed time a machine one work at in fixed time the machine work mode be a 2 times, in fixed time be worth medium TL1 to be used as to count at this time, the TH1 be used as automatically rebind a value, this in fixed time under the mode, in fixed time machine overflow after, the value of TH1 will automatically load TL1, again start count, so can need not software interfere and make in fixed time more accurate.At this in fixed time mode 2 times in fixed time machine 1 overflow the calculation formula of velocity as follows:
Overflow velocity=(count velocity)/(256 － TH1s)
Last"count velocity" within type flap with the crystal use to concuss machine frequency relevant, in 51 chips in fixed time machine start the future reunion make the value of deposit the machine TH in fixed time increase in each machine period a, a machine period equals 12 to flap to concuss a period, so can know 51 count of chipses the velocity flaps to concuss machine frequency for the crystal of 1/12, a 12 Ms of crystal flap to use on 51 chips, so 51 of count velocity is 1 M.Usually using a 11.0592 M crystal is for getting standard without any error bad of wave especially rate, why so?The calculation knew all of a sudden.Such as we good arrive 9600 waves a rate especially, crystal flap for the 11.0592 Ms and the 12 Ms, in fixed time machine 1 is mode 2, the SMOD establishes to 1 and see respectively why the TH1 that that request be worth.The generation goes into formula:
11.0592M
9600=(2 ÷s 32) ×(11.0592 Ms/12)(/(256-TH1))
TH 1=250
12M
9600=(2 ÷s 32) ×(12 Ms/12)(/(256-TH1))
TH1 ≈ 249.49
Top of the calculation can see go abroad as ambassador come out with 12 M's time calculation of the crystal of the TH1 isn't an integral, but value of TH1 can take integral, so it would the existence certain error margin can't produce 9600 of precision rate especially.The certainly certain error margin can be accept in the usage, using the crystal with 11.0592 Ms to flap to concuss a machine on the whole will also make because of the error margin exist by crystal wave especially rate creation error margin, but the error margin of crystal to wave especially the influence of the rate be very of small, can neglect not to account.