【正文】 Endurance:1000 Write/Erase Cycles 256 8Bit Internal RAM Three 16Bit Timer/Counters Eight Interrupt Sources Three Description The AT89C52 is a lowpower, highperformance CMOS 8bit microputer with 8 Kbytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is patible with the industry standard 80C51 and 80C52 instruction set and pinot. The onchip Flash allows the program memory to be reprogrammed insystem or by a conventional onvolatile memory programmer. By bining a versatile 8bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microputer, which provides a highly flexible and cost effective solution to many embedded control applications. The AT89C52 provides the following standard features: 8k bytes of Flash, 256 bytes of RAM,32 I/O lines, three 16bit timer/counters, a sixvector twolevel interrupt architecture, a full duplex serial port, onchip oscillator, and clock circuitry. In addition, the AT89C52 is designed with static 16 logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM,timer/counters,serial port,and interrupt system to continue Power Down Mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset. AT89C52 40 pins, 32 external bidirectional input / output (I / O) ports, and includes two external interrupt ports, three 16bit programmable timer counters, two full duplex serial port, 2 a readwrite port line, AT89C52 can be programmed according to conventional methods, also available online programming. The generic microprocessor and Flash memory together, particularly when repeated erase the Flash memory can effectively reduce the development costs. 。s development gradually MCU has its objective factors. MCU in the development, the most famous manufacturers when the number of Philips Corporation. Philips in embedded applications for its enormous advantages, the MCS51 from the rapid development of singlechip microputer to the microcontroller. Therefore, when we look back at the path of development of embedded systems, Intel and Philips do not fet the historical merits. 3. Singlechip is an independent embedded systems development, to the MCU an important factor in the development stage, is seeking applications to maximize the onchip solution。s hard drive is nothing, but in terms of the singlechip microputer is unacceptable. Singlechip in the utilization of hardware resources have to do very high, so the pilation of the original while still in heavy use. The same token, if the puter giant39。s series of singlechip market, the result will be different! Simply because the adoption of singlechip preparation process you can achieve high intelligence, high efficiency and high reliability! Because of the cost of singlechip is sensitive, so the dominant software or the lowest level assembly language, which is in addition to the lowest level for more than binary machine code of the language, since such a lowlevel so why should we use? Many of the senior39。s shadow! ...... It is mainly as part of the core ponents of the control. It is an online realtime control puter, controlline is at the scene, we need to have a stronger antiinterference ability, low cost, and this is offline puter (such as home PC) The main difference. By singlechip process, and can be amended. Through different procedures to achieve different functions, in particular the special unique features, this is the need to charge other devices can do a great effort, some of it is also difficult to make great efforts to do so. A function is not very plicated if the United States the development of the 5039。s close on the heels of a special processor, while the ordinary price of the model dropped to one . dollars, the most highend models, only 10 . dollars. Contemporary singlechip microputer system is no longer only the baremetal environment in the development and use of a large number of dedicated embedded operating system is widely used in the full range of singlechip microputer. In PDAs and cell phones as the core processing of highend singlechip or even a dedicated direct access to Windows and Linux operating systems. More than a dedicated singlechip processor suitable for embedded systems, so it was up to the application. In fact the number of singlechip is the world39。s with the big consumer electronics product development, singlechip technology is a huge improvement. INTEL i960 Series with subsequent ARM in particular, a broad range of applications, quickly replaced