單片機(jī)畢業(yè)設(shè)計(jì)外文文獻(xiàn)翻譯

1、<p><b>　　英文原文：</b></p><p><b>　　80C51</b></p><p>　　8051 single-chip micro-computer, referred to as microcontrollers, there are known as micro-controller, a micro-comp

2、uter re -To branch. SCM is developed in the mid 70s a large-scale integrated circuit chip, a CPU, RAM, ROM, I / O interfaces and interrupt system on the same silicon device. Since the 80s, Microcontroller rapid developm

3、ent, all kinds of new products are constantly emerging, there have been many high-performance of new models now become the field of factory automation and control of</p><p>　　Pin Function:</p><p&g

4、t;　　MCS-51 is a standard 40-pin DIP IC chip, pin distribution ---- microcontroller pin diagram please refer to: P0.0 ~ P0.7 P0 port 8-bit bidirectional port lines (in the pin 39 to No. 32 terminal). P1.0 ~ P1.7 P1 po

5、rt 8-bit bidirectional port line (pin 1 in the No. 8 terminal). P2.0 ~ P2.7 P2 port 8-bit bidirectional port lines (in the pin terminal 21 ~ 28). P3.0 ~ P3.7 P3 port 8-bit bidirectional port lines (in the pin termina

6、l 10 ~ 17).</p><p>　　This four I / O port has not exactly the same function, we can get to learn, and other books though, but written in too deep, difficult to understand for beginners, here are according to

7、 my own expression to write the I believe that you can understand.</p><p>　　P0 port has three functions:</p><p>　　1, external expansion memory, as the data bus (Figure 1 in D0 ~ D7 of data bus

8、interface)2, external expansion memory, as the address bus (Figure 1 in A0 ~ A7 to address bus interface)3, is not extended, it can do a general I / O to use, but within the supreme pull-up resistor, as an input or out

9、put should be connected to an external pull-up resistor.P1 port Zhizuo I / O port to use: its internal pull-up resistor.P2 port has two functions:1,An extended external memory when used as an addres</p><p&g

10、t;　　P3 port has two functions:As well as I / O using the external (the internal pull-up resistor), there are some special features, from a special register to set the specific features please refer to our explanation be

11、hind the pin. Internal EPROM of the microcontroller chip (for example, 8751), for the writing process required to provide specialized programming and programming pulse power, these signals are also provided in the form

12、 from the signal pin, and Namely: programming pulse: 30 feet (AL</p><p>　　In introducing the four I / O port referred to a "pull-up resistor" Then, pull-up resistor is what Dongdong do? What role d

13、oes he play? Said the resistance that is of course, is a resistor, when as an input, the pull-up resistor pulled its potential, if the input is low you can provide a current source; Therefore, if the P0 port as long as t

14、he input, in the high impedance state, only an external pull-up resistor to be effective.</p><p>　　ALE / PROG address latch control signal: in a system is extended, ALE is used to control the P0 port output

15、low 8-bit address latch latch get together in order to achieve low address and data segregation. (In the back on the expansion of the curriculum, we will see the 8051 expansion of EEPROM circuit, the ALE and the 74LS373

16、in Figure G-latches connected to the external CPU to access when the time to lock the address low address, the P0 port output. ALE may be high may also be low, when the ALE</p><p>　　In the absence of access

17、to external memory during the period, ALE 1 / 6 oscillator frequency output cycle (ie, frequency of 6 points), when access to external memory to 1 / 12 oscillator cycle, the output (12 min frequency). From here we can se

18、e that when the system does not extend when the ALE will be 1 / 6 cycle, fixed frequency oscillator output, so can be used as an external clock, or the use of an external timing pulse.</p><p>　　PORG pulse in

19、put for the program: In the fifth lesson MCU's internal structure and composition, we know that in 8051 within the a 4KB or 8KB of program memory (ROM), ROM's role is to be used to store user needs implementation

20、 of the program, then we are into how to write good programs into this ROM in it? Is actually programmed into the pulse input can be written, this pulse input port is PROG. PSEN external program memory read strobe: In

21、reading an external ROM, PSEN low effective, in order t</p><p>　　1, the internal ROM reading, PSEN is not action;</p><p>　　2, external ROM reading at each machine cycle will move twice;3, exter

22、nal RAM read, the two PSEN pulse is skipped will not be output;4, external ROM, and ROM-foot-phase OE.See Figure 2 - (8051 extension 2KB EEPROM circuit in Figure PSEN and expansion ROM in the OE pin-phase) EA / VPP a

23、ccess and sequence memory control signals1, then high time: CPU reads the internal program memory (ROM)Expansion of the external ROM: When reading the internal program memory than 0FFFH (8051) 1FFFH (8052)</p>

24、<p>　　RST Reset signal: when the input signal continuously high for more than two machine cycles when it is effective to complete the MCU reset initialization, when the reset program counter PC = 0000H, ie, after r

25、eset from the program memory of the 0000H unit to read the first script. External crystal oscillator pins XTAL1 and XTAL2. When using the chip internal clock, this two-pin for external quartz crystal and fine-tuning ca

26、pacitor; when using an external clock, used to access an external clock </p><p>　　AVR and the pic are 8051 different structures with 8-bit microcontrollers, because structure is different, so assembly instru

27、ctions are different, but distinct from the use of CISC instruction set of the 8051, they are RISC instruction set, and only a few dozen instructions, most instructions are single instruction cycle instruction, so in the

28、 same crystal frequency, faster than the 8051. Another PIC 8-bit microcontroller in previous years, is the world's largest MCU shipments, followed by Frees</p><p><b>　　中文譯文：</b></p>&l

29、t;p><b>　　8051</b></p><p>　　單片微型計(jì)算機(jī)簡(jiǎn)稱為單片機(jī)，又稱為微型控制器，是微型計(jì)算機(jī)的一個(gè)重要分支。單片機(jī)是70年代中期發(fā)展起來的一種大規(guī)模集成電路芯片，是CPU、RAM、ROM、I/O接口和中斷系統(tǒng)于同一硅片的器件。80年代以來，單片機(jī)發(fā)展迅速，各類新產(chǎn)品不斷涌現(xiàn)，出現(xiàn)了許多高性能新型機(jī)種，現(xiàn)已逐漸成為工廠自動(dòng)化和各控制領(lǐng)域的支柱產(chǎn)業(yè)之一。</p

30、><p><b>　　引腳功能： </b></p><p>　　MCS-51是標(biāo)準(zhǔn)的40引腳雙列直插式集成電路芯片，引腳分布請(qǐng)參照----單片機(jī)引腳圖： </p><p>　　P0.0~P0.7 P0口8位雙向口線（在引腳的39~32號(hào)端子）。 </p><p>　　P1.0~P1.7 P1口8位雙向口線（在引腳的1~8號(hào)端

31、子）。 </p><p>　　P2.0~P2.7 P2口8位雙向口線（在引腳的21~28號(hào)端子）。 </p><p>　　P3.0~P3.7 P3口8位雙向口線（在引腳的10~17號(hào)端子）。 </p><p>　　這4個(gè)I/O口具有不完全相同的功能，大家可得學(xué)好了，其它書本里雖然有，但寫的太深，初學(xué)者很難理解，這里都是按我自已的表達(dá)方式來寫的，相信你也能夠理解。 &

32、lt;/p><p>　　P0口有三個(gè)功能： </p><p>　　1、外部擴(kuò)展存儲(chǔ)器時(shí)，當(dāng)做數(shù)據(jù)總線（如圖1中的D0~D7為數(shù)據(jù)總線接口） </p><p>　　2、外部擴(kuò)展存儲(chǔ)器時(shí)，當(dāng)作地址總線（如圖1中的A0~A7為地址總線接口） </p><p>　　3、不擴(kuò)展時(shí)，可做一般的I/O使用，但內(nèi)部無上拉電阻，作為輸入或輸出時(shí)應(yīng)在外部接上拉電阻。

33、 </p><p>　　P1口只做I/O口使用：其內(nèi)部有上拉電阻。 </p><p>　　P2口有兩個(gè)功能： </p><p>　　1、擴(kuò)展外部存儲(chǔ)器時(shí)，當(dāng)作地址總線使用 </p><p>　　2、做一般I/O口使用，其內(nèi)部有上拉電阻； </p><p>　　P3口有兩個(gè)功能： </p><p>

34、;　　除了作為I/O使用外（其內(nèi)部有上拉電阻），還有一些特殊功能，由特殊寄存器來設(shè)置，具體功能請(qǐng)參考我們后面的引腳說明。 </p><p>　　有內(nèi)部EPROM的單片機(jī)芯片（例如8751），為寫入程序需提供專門的編程脈沖和編程電源，這些信號(hào)也是由信號(hào)引腳的形式提供的，即：編程脈沖：30腳（ALE/PROG）編程電壓（25V）：31腳（EA/Vpp）（注：這些引腳的功能應(yīng)用，除9腳的第二功能外，在“新動(dòng)力2004版

35、”學(xué)習(xí)套件中都有應(yīng)用到。） </p><p>　　在介紹這四個(gè)I/O口時(shí)提到了一個(gè)“上拉電阻”那么上拉電阻又是什么呢？他起什么作用呢？都說了是電阻那當(dāng)然就是一個(gè)電阻啦，當(dāng)作為輸入時(shí)，上拉電阻將其電位拉高，若輸入為低電平則可提供電流源；所以如果P0口如果作為輸入時(shí)，處在高阻抗?fàn)顟B(tài)，只有外接一個(gè)上拉電阻才能有效。 ALE/PROG 地址鎖存控制信號(hào)：在系統(tǒng)擴(kuò)展時(shí)，ALE用于控制把P0口的輸出低8位地址送鎖存器鎖

36、存起來，以實(shí)現(xiàn)低位地址和數(shù)據(jù)的隔離。（在后面關(guān)于擴(kuò)展的課程中我們就會(huì)看到8051擴(kuò)展 EEPROM電路，在圖中ALE與74LS373鎖存器的G相連接，當(dāng)CPU對(duì)外部進(jìn)行存取時(shí)，用以鎖住地址的低位地址，即P0口輸出。ALE有可能是高電平也有可能是低電平，當(dāng)ALE是高電平時(shí)，允許地址鎖存信號(hào)，當(dāng)訪問外部存儲(chǔ)器時(shí)，ALE信號(hào)負(fù)跳變（即由正變負(fù)）將P0口上低8位地址信號(hào)送入鎖存器。當(dāng)ALE是低電平時(shí)，P0口上的內(nèi)容和鎖存器輸出一致。關(guān)于鎖存器的

37、內(nèi)容，我們稍后也會(huì)介紹。 </p><p>　　在沒有訪問外部存儲(chǔ)器期間，ALE以1/6振蕩周期頻率輸出（即6分頻），當(dāng)訪問外部存儲(chǔ)器以1/12振蕩周期輸出（12分頻）。從這里我們可以看到，當(dāng)系統(tǒng)沒有進(jìn)行擴(kuò)展時(shí)，ALE會(huì)以1/6振蕩周期的固定頻率輸出，因此可以做為外部時(shí)鐘，或者外部定時(shí)脈沖使用。 　</p><p>　　PORG為編程脈沖的輸入端：在第五課 單片機(jī)的內(nèi)部結(jié)構(gòu)及其組成中，我們

38、已知道，在8051單片機(jī)內(nèi)部有一個(gè)4KB或8KB的程序存儲(chǔ)器（ROM），ROM的作用就是用來存放用戶需要執(zhí)行的程序的，那么我們是怎樣把編寫好的程序存入進(jìn)這個(gè)ROM中的呢？實(shí)際上是通過編程脈沖輸入才能寫進(jìn)去的，這個(gè)脈沖的輸入端口就是PROG。 </p><p>　　PSEN 外部程序存儲(chǔ)器讀選通信號(hào)：在讀外部ROM時(shí)PSEN低電平有效，以實(shí)現(xiàn)外部ROM單元的讀操作。 </p><p>　　1

39、、內(nèi)部ROM讀取時(shí)，PSEN不動(dòng)作； </p><p>　　2、外部ROM讀取時(shí)，在每個(gè)機(jī)器周期會(huì)動(dòng)作兩次； </p><p>　　3、外部RAM讀取時(shí)，兩個(gè)PSEN脈沖被跳過不會(huì)輸出； </p><p>　　4、外接ROM時(shí)，與ROM的OE腳相接。 </p><p>　　參見圖2—（8051擴(kuò)展2KB EEPROM電路，在圖中PSEN與擴(kuò)展

40、ROM的OE腳相接） </p><p>　　EA/VPP 訪問和序存儲(chǔ)器控制信號(hào) </p><p><b>　　1、接高電平時(shí)： </b></p><p>　　CPU讀取內(nèi)部程序存儲(chǔ)器（ROM） </p><p>　　擴(kuò)展外部ROM：當(dāng)讀取內(nèi)部程序存儲(chǔ)器超過0FFFH（8051）1FFFH（8052）時(shí)自動(dòng)讀取外部ROM

41、。 </p><p>　　2、接低電平時(shí)：CPU讀取外部程序存儲(chǔ)器（ROM）。 在前面的學(xué)習(xí)中我們已知道，8031單片機(jī)內(nèi)部是沒有ROM的，那么在應(yīng)用8031單片機(jī)時(shí)，這個(gè)腳是一直接低電平的。 </p><p>　　3、8751燒寫內(nèi)部EPROM時(shí)，利用此腳輸入21V的燒寫電壓。 </p><p>　　RST 復(fù)位信號(hào)：當(dāng)輸入的信號(hào)連續(xù)2個(gè)機(jī)器周期以上高電平時(shí)即為有

42、效，用以完成單片機(jī)的復(fù)位初始化操作，當(dāng)復(fù)位后程序計(jì)數(shù)器PC=0000H，即復(fù)位后將從程序存儲(chǔ)器的0000H單元讀取第一條指令碼。 </p><p>　　XTAL1和XTAL2 外接晶振引腳。當(dāng)使用芯片內(nèi)部時(shí)鐘時(shí)，此二引腳用于外接石英晶體和微調(diào)電容；當(dāng)使用外部時(shí)鐘時(shí)，用于接外部時(shí)鐘脈沖信號(hào)。 </p><p>　　VCC：電源+5V輸入 </p><p>　　VSS：

43、GND接地。 </p><p>　　AVR和pic都是跟8051結(jié)構(gòu)不同的8位單片機(jī)，因?yàn)榻Y(jié)構(gòu)不同，所以匯編指令也有所不同，而且區(qū)別于使用CISC指令集的8051,他們都是RISC指令集的，只有幾十條指令，大部分指令都是單指令周期的指令，所以在同樣晶振頻率下，較8051速度要快。另PIC的8位單片機(jī)前幾年是世界上出貨量最大的單片機(jī)，飛思卡爾的單片機(jī)緊隨其后。</p><p>　　ARM實(shí)際

44、上就是32位的單片機(jī)，它的內(nèi)部資源（寄存器和外設(shè)功能）較8051和PIC、AVR都要多得多，跟計(jì)算機(jī)的CPU芯片很接近了。常用于手機(jī)、路由器等等。</p><p>　　DSP其實(shí)也是一種特殊的單片機(jī)，它從8位到32位的都有。它是專門用來計(jì)算數(shù)字信號(hào)的。在某些公式運(yùn)算上，它比現(xiàn)行家用計(jì)算機(jī)的最快的CPU還要快。比如說一般32位的DSP能在一個(gè)指令周期內(nèi)運(yùn)算完一個(gè)32位數(shù)乘32位數(shù)積再加一個(gè)32位數(shù)，應(yīng)用于某些對(duì)實(shí)時(shí)