【正文】 her than approximate results with lookup tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and generalpurpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8and 16bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other generalpurpose‘C2xx generation ,source code patible with the’C2x generation , and upwardly source code patible with the ‘C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also wellsuited for processing control signals. It uses a 16bit word length along with 32bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This bination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The ‘C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixedsignal peripherals includes:TimersSerial munications ports (SCI,SPI)Analogtodigital converters(ADC)Event managerSystem protection, such as lowvoltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marketplace.The TMS320F/C240 is the first standard device introduced in the ‘24x series of DSP controllers. It sets the standard for a singlechip digital motor controller. The ‘240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows realtime execution of very ple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessary for highspeed signal processing and digital control functions, and it has the peripherals needed to provide a singlechip solution for motor control applications. The ‘240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several powerdown modes for further power savings. Some applications that benefit from the advanced processing power of the ‘240 include: Industrial motor drivesPower inverters and controllersAutomotive systems, such as electronic power steering , antilock brakes, and climate controlAppliance and HVAC blower/ pressor motor controlsPrinters, copiers, and other office productsTape drives, magnetic optical drives, and other mass storage productsRobotic and CNC milling machinesTo function as a system manager, a DSP must have robust onchip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This applicationoptimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for highprecision and highefficiency full variablespeed control of all motor types. Include in the event manager are special pulsewidth modulation (PWM) generation functions, such as a programmable deadband function and a space vector PWM state machine for 3phase motors that provides stateoftheart maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own pare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.OpenLoop and ClosedLoop ControlOpenloop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an openloop system , which is the simplest and most economical type of control lies in the fact that one may not know the exact characteristics of the further ,which has