【正文】 51BH, 80C31BH,etc., their basic position, basic performance and instruction system are all the daily representatives51 serial onechip puters. A onechip puter system is made up of several following parts: (1) One microprocessor of 8 (CPU). ( 2) At slice data memory RAM (128B/256B),it use not depositing not can reading /data that write, such as result not middle of operation, final result and data wanted to show, etc. (3) Procedure memory ROM/EPROM (4KB/8KB ), is used to preserve the procedure , some initial data and form in slice. But does not take ROM/EPROM within some onechip puters, such as 8031, 8032.(4) Four 8 run side by side I/O interface P0 four P3, each mouth can use as introduction , may use as exporting too. (5) Two timer / counter, each timer / counter may set up and count in the way, used to count to the external incident, can set up into a timing way too, and can according to count or result of timing realize the control of the puter. (6) Five cut off cutting off the control system of the source. (7) One all duplex serial I/O mouth of UART (universal asynchronous receiver/transmitter (UART) ), is it realize onechip puter or onechip puter and serial munication of puter to use for. (8) Stretch oscillator and clock produce circuit, quartz crystal finely tune electric capacity need outer. Allow oscillation frequency as 12 megahertz now at most. Every the abovementioned part was joined through the inside data bus .Among them, CPU is a core of the onechip puter, it is the control of the puter and mand centre, made up of such parts as arithmetic unit and controller , etc.. The arithmetic unit can carry on 8 persons of arithmetic operation and unit ALU of logic operation while including one, the 1 storing device temporaries of 8, storing device 2 temporarily, 839。 when resistance value is very large, P1 mouth high electricity at ordinary times, can is it draw electric current load to offer outwards, draw electric current load to offer outwards, draw the resistance on needn39。clock, can output W line signal. At the time of programming, it is that the first function is still the second function but needn39。s head and monitor the pin with the oscilloscope tentatively, push and is restored to the throne the key, the wave form that observes and has enough range is exported (instantaneous), can also through is it restore to the throne circuit group holding value carry on the experiment to change. MCS51系列單片機的功能和結(jié)構(gòu) MSC51 系列單片機具有一個單芯片電腦的結(jié)構(gòu)和功能，它是英特爾公司的系列產(chǎn)品的名稱。 一個單芯片的計算機是由以下幾個部分組成：（ 1）一個 8 位的微處理器（ CPU）。（ 5）兩個定時 /計數(shù)器， 每個定時方式也可以根據(jù)計算結(jié)果或定時控制實現(xiàn)計算機。其中 CPU 是一個芯片計算機的核心，它是計算機的指揮中心，是由算術(shù)單元和控制器等部分組成。振蕩器和定時電路等的程序計數(shù)器是一個由 8 個計數(shù)器為 2，總計 16 位。這種脈沖信號，作為 8051 的工作，即單位時間的最低基本節(jié)奏。數(shù)據(jù)80518751 的內(nèi)存數(shù)據(jù)存儲器 128B）條 8031，地址虛假 00FH，中層結(jié)果存入操作使用，數(shù)據(jù)存儲和數(shù)據(jù)暫時緩沖等。在訪問內(nèi)存，相應(yīng)的，只有一個地址的內(nèi)存單 元，可以用外部存儲，也可以內(nèi)存，并通過訪問順序與此類似。但是，從用戶使用， 8051 的內(nèi)存地址空間分為三種：分為（ 1）片內(nèi)，（使用 16 個地址一致的 FFFFH，地點為0000H）。 8051 單芯片的電腦有 4 個 8 步行并進的 I/O 端口，分別為 P0,P1,P2和 P3。使數(shù)據(jù)能鎖存輸出時，數(shù)據(jù)緩沖區(qū)時，可以引 進，但 4 個通道這些自我相同的功能。熟悉 I/O端口的邏輯電路，不僅有助于正確和合理利用端口，并在一定程度上將有助于設(shè)計周邊的單芯片計算機的邏輯電路。當被用作數(shù)據(jù)，應(yīng)該寫“ 1”到內(nèi)部，每一個 P0 口與一個可以驅(qū)動 8 型號 LS TTL 負載出口。另一條是它可以導致在來兩個工作狀態(tài)密切，使其電阻值變化近似 0 或 2 阻值的情況非常嚴重。相對約 20200 歐姆，因為在現(xiàn)場，負載電阻和40000 歐姆，不會產(chǎn)生對輸入的數(shù)據(jù)的影響。法令： Q=1 時，可以輸出 W 線路信號，在制定方案的時候，那就是第一個函數(shù)仍是第二個功能，但不必軟件預(yù)先設(shè)置 P3 口。因為他們利用輸出級阻力，可以打開漏源電阻以敦促打開方式，不需要有阻力。其主要功能是把最初的 PC 為0000H，使單芯片電腦開始持有單位 0000H 開始執(zhí)行程序的行為。如果是有頻率 6，恢復位的信號持續(xù)時間應(yīng)超過 4 微秒完成恢復。作為恢復到電路，其功能是非常重