苏州科技学院天平学院本科生毕业设计（论文）
附录B 外文原文
STC89C52 processing chip
Prime features:
With MCS - 51 SCM product compatibility, 8K bytes in the system programmable Flash memory, 1000 times CaXie cycle, the static operation: 0Hz ~ 33Hz, triple encryption program memory, 32 programmed I/O port, three 16 timer/counter, the eight uninterrupted dual-career UART serial passage, low power consumption, leisure and fall after fall electric power mode can be awakened and continuous watchdog timer and double-number pointer, power identifier.
Efficacy: characteristics
STC89C52 is one kind of low power consumption, high CMOS8 bit micro-controller, 8K in system programmable Flash memory. Use high-density nonvolatile storage technology, and industrial 80C51 product instruction and pin fully compatible. The Flash memory chips allows programs in the system, also suitable for programmable conventional programming. In a single chip, have clever 8 bits CPU and online system programmable Flash, increase STC89C52 for many embedded control system to provide high vigorous application and useful solutions. STC89C52 has following standard efficacy: 8k byte Flash RAM, 256 bytes, 32 I/O port, the watchdog timer, two, three pointer numerical 16 timer/counter, a 6 vector level 2 continuous structure, the serial port, working within crystals and horological circuit. In addition, 0Hz AT89S52 can drop to the static logic operation, support two software can choose power saving mode. Idle mode, the CPU to stop working, and allows the RAM, timer/counters, serial, continuous to work. Protection asana pattern, RAM
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苏州科技学院天平学院本科生毕业设计（论文）
content is survival, vibrators frozen, SCM, until all the work under a continuous or hardware reset. 8-bit microcontrollers 8K bytes in the system programmable Flash AT89S52 devices.
Mouth: P0 P0 mouth is a two-way open drain I/O. As export, each can drive eight TTL logic level. For P0 port to write \impedance input.
When access to external programs and numerical memory, also known as low P0 mouth eight address/numerical reuse. In this mode, with the internal P0 resistor.
In the flash when programming, also used for P0 mouth; absorb instruction bytes In the process, the output command byte calibration. When the program requires external, calibration on pull-up resistors.
Mouth: P1 mouth P1 is an internal resistance of the eight two-way I/O buffers can drive, P1 output four TTL logic level. To write \the internal resistance to port, can push as input mouth. When used as input, external and internal foot because of low resistance, will output current (IIL).
In addition, P1.0 and P1.2 respectively timer/counter 2 external counting input (P1.0 / T2) and when the trigger editor/counter P1.1 input (2), specific T2EX/are shown below. In programming and calibration, flash P1 mouth absorb eight address low byte.
Efficacy: the foot.
P1.0 T2 (timer/counter T2 external counting input), clock output P1.1 T2EX (timer/counter T2 capture/overloaded triggered signals and direction control),
P1.5 MOSI (with) online system programming, P1.6 MISO (with) online system programming, P1.7 SCK (with) online system programming,
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苏州科技学院天平学院本科生毕业设计（论文）
Mouth: P2 P2 mouth is an internal resistance of the eight two-way I/O buffers and P2 output can drive four TTL logic level. To write \P2 port, the internal resistance to port, can push as input mouth. When used as input, external and internal foot because of low resistance, will output current (IIL).
In the external program memory access or use 16bit external numerical memory address read (for example MOVX execution DPTR @), P2 mouth send out high 8 address. In this application, P2 mouth on the internal use strong pull send 1. In using 8-bit address (such as MOVX @ RI) access to external numerical memory, P2 mouth output P2 latches content. In programming and calibration, flash P2 mouth also absorb high eight address byte and some control signal.
P3: a P3 mouth on the inside of the eight two-way pull-up resistors I/O buffers can drive, p2 output four TTL logic level. For P3 port to write \to port, can push as input mouth. When used as input, external and internal foot because of low resistance, will output current (IIL). P3 mouth AT89S52 special functions (also as the second efficacy), are shown below. In programming and calibration, flash also absorb some P3 mouth control signals.
Port pin second efficacy: P3.0 RXD (serial input) P3.1 TXD (serial export), P3.2 INTO the discontinuous (0) P3.3 INT1 (1) the discontinuous P3.4 (time/counter TO 0) P3.5 T1 (1) time/counter,
P3.6 WR (external numerical memory write for) P3.7 RD (external numerical memory read for)
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苏州科技学院天平学院本科生毕业设计（论文）
In addition, also absorb some used in mp3 mouth FLASH memory programming and calibration of program control signals.
RST, reset input: when the vibrator, RST pin appeared two machine cycle above high level will be reset the chip.
ALE/PROG - when access to external program memory or numerical memory, ALE (address latch allow) output pulses are used to latch address of low eight bytes. Normally, ALE with clock frequencies are 1/6 output pulse signal with fixed, so it can be used for the purpose or output clocks. Timing Those who want an attention is: whenever access to external numerical memory will skip a ALE pulse.
For FLASH memory programming, this pin is used for input programming pulse (.) PROG
If necessary, but through special effect to the zone registers (SFR) 8EH D0 position, the unit can be banned ALE operations. This position is a bit, MOVX and MOVC instructions will be activated. ALE -- In addition, the foot will be weak, execute external program MCU hign should be banned, a void. Set ALE
PSEN - program storage PSEN allowed (output is outside of the program memory read, choose communication by external program memory when taking AT89C52 instructions (or), each machine cycle PSEN twice, two pulse output is useful, during this period, when access to external numerical memory, will skip PSEN twice.
EA/VPP - external access permission, to make the CPU only access to external program memory (address for 0000H - FFFFH), EA end must remain low level (ground). Should notice is: if a LB1 is encrypted, reset when programming will latch EA end.
As for the high level of the EA (VCCS), the CPU is the implementation of the program memory internal instructions.
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苏州科技学院天平学院本科生毕业设计（论文）
FLASH memory when programming, this pin plus + 12 v programming allow power Vpp, of course, that is the part is used to Vpp voltage 12V programming.
Actual problem ability contacting actual solving by the fact that graduation practice, improves theory; Going deep into waiting for relevance hardware knowledge to interface technology understands rise; Have 8279's control words interposition , mechanics , programming principle and PC interface method in hand. Deepen the characteristic and operating principle understanding the successive approximation law modulus converter's , have the ADC0809 interface method and A/D input program design in hand and test method. It is known to all that not caring now is enterprise , a factory , is still a family, having realized an automation mainly , be that a little intellectualized equipment has been used , such has been provided immense going to the lavatory to the user. Thought and operation intellectualized , being to have let treatment element replace person, come to control the outside equipment job.
The relay, is that a representative example (modern times automates to have circuital mutual a electron and electricity linkup problem in control system , one side needs to make the electronic circuit pilot signal be able to control the circuital electricity implementation component (electric motor , electromagnet , electric lamp etc.); Electricity being going to be an electronic circuit again on one hand provide fine electricity isolation, to protect the electronic circuit and person's safety, the electron relay just can accomplish this one bridge effect). Should design the aspect being to have embodied a little intelligence. Come to reach the purpose reaching electrical equipment , the electric motor job under the control of changing simulation amounts unceasingly. Be concretely: The chip centering on 8086, 0809, 8255 grades, uses single
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