Structure and function of the MCS-51 series
The MCS-51 series one-chip computer MCS-51 is a name of a piece of one-chip computer series which Intel Company produces. This company introduced 8 top-grade one-chip computers of MCS-51 series in 1980 after introducing 8 one-chip computers of MCS-48 series in 1976. It belong to a lot of kinds this line of one-chip computer the chips have,such as 8051, 8031, 8751, 80C51BH, 80C31BH,etc., their basic composition, basic performance and instruction system are all the same. 8051 daily representatives- 51 serial one-chip computers .
51系列单片机是由英特尔公司生产的的单片机产品。该家公司在1976年发行了8位MCS-48系列。然后又在在1980年推出了高8位的MCS-51系列单片机。它属于这一类型很多行一个芯片的电脑芯片都如8051、8031、8751、
80c51bh,80c31bh等,其基本组成、性能和基本教学制度,都是一样的. 8051通常是51系列的代表。
An one-chip computer 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 depositting 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 one-chip computers, such as 8031 , 8032, 80C ,etc.. ( 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 computer. ( 6) Five cut off cutting off the control system of the source . ( 7) One all duplexing serial I/O mouth of UART (universal asynchronous
receiver/transmitter (UART) ), is it realize one-chip computer or one-chip computer and serial communication of computer to use for. ( 8) Stretch oscillator and clock produce circuit, quartz crystal finely tune electric capacity need outer. Allow oscillation frequency as 12 megahertas now at most. Every the above-mentioned part was joined through the inside data bus .Among them, CPU is a core of the one-chip computer, it is the control of the computer and command 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 temporarilies of 8, storing device 2 temporarily, 8's accumulation device ACC, register B and procedure state register PSW, etc. Person who accumulate ACC count by 2 input ends entered of checking etc. temporarily as one operation often, come from person who store 1 operation is it is it make operation to go on to count temporarily , operation result and loopback ACC with another one. In addition, ACC is often regarded as the transfer station of data transmission on 8051 inside . The same as general microprocessor, it is the busiest register. Help remembering that agreeing with A expresses in the order. The controller includes the procedure counter , the order is depositted, the order decipher, the oscillator and timing circuit, etc. The procedure counter is made up of counter of 8 for two, amounts to 16. It is a byte address counter of the procedure in fact, the content is the next IA that will carried out in PC. The content which changes it can change the direction that the procedure carries out . Shake the circuit in 8051 one-chip computers, only need outer quartz crystal and frequency to finely tune the electric capacity, its frequency range is its 12MHZ of 1.2MHZ. This pulse signal, as 8051 basic beats of working, namely the minimum unit of time. 8051 is the same as other computers, the work in harmony under the control of the basic beat, just like an orchestra according to the beat play that is commanded.
