【正文】 o read, they have each independent memory address space, dispose way to be the same with general memory of puter. Procedure 8051 memory and 8751 slice procedure memory capacity 4KB, address begin from 0000H, used for preserving the procedure and form constant. Data 8051 8751 8031 of memory data memory 128B, address false 00FH, use for middle result to deposit operation, the data are stored temporarily and the data are buffered etc.. In RAM of this 128B, there is unit of 32 byteses that can be appointed as the job register, this and general microprocessor is different, 8051 slice RAM and job register rank one formation the same to arrange the location. It is not very the same that the memory of MCS51 series onechip puter and general puter disposes the way in addition. General puter for first address space, ROM and RAM can arrange in different space within the range of this address at will, namely the addresses of ROM and RAM, with distributing different address space in a formation. While visiting the memory, corresponding and only an address Memory unit, can ROM, it can be RAM too, and by visiting the order similarly. This kind of memory structure is called the structure of Princeton. 8051 memories are divided into procedure memory space and data memory space on the physics structure, there are four memory spaces in all: The procedure stores in one and data memory space outside data memory and one in procedure memory space and one outside one, the structure forms of this kind of procedure device and data memory separated form data memory, called Harvard structure. But use the angle from users, 8051 memory address space is divided into three kinds: (1) In the slice, arrange blocks of FFFFH , 0000H of location , in unison outside the slice (use 16 addresses). (2) The data memory address space outside one of 64KB, the address is arranged from 0000H 64KB FFFFH (with 16 addresses ) too to the location. (3) Data memory address space of 256B (use 8 addresses). Three abovementioned memory space addresses overlap, for distinguishing and designing the order symbol of different data transmission in the instruction system of 8051: CPU visit slice, ROM order spend MOVC , visit block RAM order uses MOVX outside the slice, RAM order uses MOV to visit in slice. 8051 onechip puter have four 8 walk abreast I/O port, call P0, P1, P2 and P3. Each port is 8 accurate twoway mouths, accounts for 32 pins altogether. Every one I/O line can be used as introduction and exported independently. Each port includes a latch (namely special function register ), one exports the driver and a introduction buffer . Make data can latch when outputting, data can buffer when making introduction , but four function of passway these selfsame. Expand among the system of memory outside having slice, four port these may serve as accurate twoway mouth of I/O in mon use. Expand among the system of memory outside having slice, P2 mouth see high 8 address off。一個單片機(jī)的系統(tǒng)是由以下幾部分組成：(1)一個8位CPU微處理器。(8)振蕩器和時鐘產(chǎn)生電路，需要外部電源的石英晶體微調(diào)電路，允許接在12V的振蕩頻率上。該程序計數(shù)器是有兩對8或16位計數(shù)器，它是一個字節(jié)地址計數(shù)器，在個人電腦運行程序時，執(zhí)行下一個單元的內(nèi)容，程序執(zhí)行時可以改變它的內(nèi)容從而改變運行的結(jié)果。MCS 51系列單片機(jī)和一般電腦的處理方式不同。上述三個重疊的內(nèi)存空間地址，用8051指令系統(tǒng)的傳輸不同的數(shù)據(jù)和使用的功能區(qū)分。P3口的輸出級別小于P1，可以在里面繪制負(fù)載電阻，每一個都能驅(qū)動4個LS型TTL負(fù)載輸出。在8051中RST引腳是一個輸入復(fù)位鍵，復(fù)位鍵高電平信號有效，要保證24倍以上的時鐘周期（即2個機(jī)器周期）。附錄C：源代碼include //頭文件include define uchar unsigned char //宏定義define uint unsigned int sbit beep1=P1^0。sbit k5=P3^4。void sound2()。i120。 IP = 0x01。 if(K2==0) //按鍵2是否按下 sound2()。 uchar y。a) //a循環(huán)用變量,影響聲音 { beep1=0。 } for(b=200。a) { beep2=0。 } for(b=200。a) { beep3=0。 }for(b=200。a) { beep4=0。 } for(b=200。 //延時 Led=1。}void T1_INT() interrupt 3{ TH0 = 45000/256。ta damagesbased agreement, you should make sure you39。s about how he felt and I would like to speak to him first to find out what his experience was.Uefa has May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.　　一字開頭的年齡已經(jīng)到了尾聲。t reall。s actions.CSKA said they were surprised and disappointed by Toure39。s 150th anniversary celebrations and will attend City39。t charge you more than 35% of your pensation your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, see TL0 = FRQ。 }}void Open(){ Led=0。c0。 }}void sound4(){ for(a=200。c0。 }}void sound3(){for(a=200。c0。 }}void sound2(){ for(a=200。c0。}void sound1() //蜂鳴器發(fā)聲子函數(shù){ for(a=200。 if(k8==0) Open()。 Delayms(1)。 IT0 = 1。 void Delayms(uint ms) //毫秒延遲函數(shù){ uchar i。void delay(uint z)。sbit K3=P1^5。一個單片機(jī)系統(tǒng)能否正常運行，應(yīng)先檢查它有沒有正確的復(fù)位電路。其主要功能是把初始地址設(shè)為0000H，使單片機(jī)從0000H的地址開始運行程序。使數(shù)據(jù)能夠鎖存輸出，數(shù)據(jù)可以及時緩沖，其余四個具有相同的功能。（2）外部數(shù)據(jù)存儲器地址空間為64KB，地址是從0000H到 FFFFH（含16個地址）的位置排列也。8058758031數(shù)據(jù)存儲器的內(nèi)存為128B，默認(rèn)地址是00FH，用于保存中間數(shù)據(jù)和緩存。有記憶功能并執(zhí)行命令。(6)五個中斷源控制系統(tǒng)。它包含很多種這類型的單片機(jī)，如8051，8031，8751，80C51BH，80C31BH等，它們的基本組成，基本性能和指令系統(tǒng)都是一樣的。在四年的大學(xué)生涯里，還得到眾多老師的關(guān)心支持和幫助。當(dāng)按下開關(guān)k5至k8的任意一個時LED燈就會點亮,，LED燈點亮就表示大門的開啟。打開proteus軟件，在File的下拉菜單中找到New Design新建Proteus并選擇A4版面，然后保存，這樣就完成proteus的新建了。它不僅具有其它仿真軟件的仿真功能，還能仿真單片機(jī)及外圍器件。點擊Build target編譯C語言程序，檢查程序是否有錯。用過匯編語言后再使用C來開發(fā)，體會更加深刻。圖 室內(nèi)門鈴電路原理圖 元件分類和清單 基于單片機(jī)的多用戶門鈴的設(shè)計，所需要的元件的所屬分類和清單列表如表42所示。當(dāng)芯片有電平的變化就會使蜂鳴器導(dǎo)通，使其工作發(fā)出蜂鳴聲，從而實現(xiàn)門鈴的作用。 晶振電路原理圖 復(fù)位電路當(dāng)輸入的信號連續(xù)2個機(jī)器周期以上高電平時即為有效，用以完成單片機(jī)的復(fù)位初始化操作，當(dāng)復(fù)位后程序計數(shù)器PC=0000H，即復(fù)位后將從程序存儲器的0000H單元讀取第一條指令碼。ATAL1和XTAL2T89S51引腳X與晶體振蕩器及電容CC1按圖42所示方式連接。 　　XTAL1：片內(nèi)晶振電路反向放大器輸出端接CPU內(nèi)部時鐘電路。另外,該引腳被略微拉高。當(dāng)振蕩器復(fù)位器件時,要保持RST腳兩個機(jī)器周期的高電平時間。P2口當(dāng)用于外部程序存儲器或16位地址外部數(shù)據(jù)存儲器進(jìn)行存取時,P2口輸出地址的高八位。P0能夠用于外部程序數(shù)據(jù)存儲器,它可以被定義為數(shù)據(jù)/地址的第八位。該方案可以驅(qū)動八個負(fù)載，本文選擇四個，其余端口可作為擴(kuò)展時使用。在片外：尋址范圍有64KB；芯片引腳有40個。住戶聽到門鈴的響起，知道有