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1、关于单片机的英文文献The General Situation of AT89C51Microcontrollers are used in a multitude of commercial applications such as modems, motor-control systems， air conditioner control systems, automotive engine and among others. The high processing speed and enhanced peripheral set of these microcontrollers ma
2、ke them suitable for such high-speed event-based applications。 However, these critical application domains also require that these microcontrollers are highly reliable。 The high reliability and low market risks can be ensured by a robust testing process and a proper tools environment for the validat
3、ion of these microcontrollers both at the component and at the system level. Intel Platform Engineering department developed an object-oriented multithreaded test environment for the validation of its AT89C51 automotive microcontrollers. The goals of this environment was not only to provide a robust
4、 testing environment for the AT89C51 automotive microcontrollers, but to develop an environment which can be easily extended and reused for the validation of several other future microcontrollers。 The environment was developed in conjunction with Microsoft Foundation Classes （AT89C51). The paper des
5、cribes the design and mechanism of this test environment， its interactions with various hardware/software environmental components， and how to use AT89C51。1.1 IntroductionThe 8bit AT89C51 CHMOS microcontrollers are designed to handle highspeed calculations and fast input/output operations。 MCS 51 mi
6、crocontrollers are typically used for high-speed event control systems。 Commercial applications include modems， motorcontrol systems, printers, photocopiers， air conditioner control systems， disk drives， and medical instruments。 The automotive industry use MCS 51 microcontrollers in engine-control s
7、ystems， airbags, suspension systems， and antilock braking systems （ABS）. The AT89C51 is especially well suited to applications that benefit from its processing speed and enhanced onchip peripheral functions set， such as automotive powertrain control, vehicle dynamic suspension, antilock braking, and
8、 stability control applications. Because of these critical applications， the market requires a reliable cost-effective controller with a low interrupt latency response, ability to service the high number of time and event driven integrated peripherals needed in real time applications, and a CPU with
9、 above average processing power in a single package. The financial and legal risk of having devices that operate unpredictably is very high. Once in the market， particularly in mission critical applications such as an autopilot or anti-lock braking system， mistakes are financially prohibitive. Redes
10、ign costs can run as high as a $500K， much more if the fix means 2 back annotating it across a product family that share the same core and/or peripheral design flaw. In addition， field replacements of components is extremely expensive, as the devices are typically sealed in modules with a total valu
11、e several times that of the component. To mitigate these problems， it is essential that comprehensive testing of the controllers be carried out at both the component level and system level under worst case environmental and voltage conditions。 This complete and thorough validation necessitates not o
12、nly a well-defined process but also a proper environment and tools to facilitate and execute the mission successfully。 Intel Chandler Platform Engineering group provides post silicon system validation （SV) of various micro-controllers and processors. The system validation process can be broken into
13、three major parts。 The type of the device and its application requirements determine which types of testing are performed on the device。1。2 The AT89C51 provides the following standard features: 4Kbytes of Flash, 128 bytes of RAM， 32 I/O lines， two 16bittimer/counters， a five vector two-level interru
14、pt architecture, a full duple serial port， onchip oscillator and clock circuitry。 In addition, the AT89C51 is designed with static 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， s
15、erial port and interrupt sys -tem to continue functioning. The Powerdown Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset。13Pin DescriptionVCC Supply voltage.GND Ground.Port 0:Port 0 is an 8-bit open-drain bidirectional I/O port.
16、 As an output port， each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs .Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification。 External pullups are required durin
