【正文】 ecrease of CPU burden and steady work generally has several functions such as overcurrent protection, deadtime adjustment and so on. Then the method has been widely used in many kinds of occasion now. (4) Generated by PWM function module of MCU. Through embedding PWM function module in MCU and initializing the function, PWM pins of MCU can also automatically generate PWM out signals without CPU controlling only when need to change dutycycle. It is the method that will be implemented in this paper. In this paper, we propose a PWM module embedded in a 8051 microcontroller. The PWM module can support PWM pulse signals by initializing the control register and dutycycle register with three methods just mentioned above to adjust the duty cycle and several operation modes to add flexibility for user. The following section explains the architecture of the PWM module and the architectures of basic functional blocks. Section3 describes two operation modes. Experimental and simulation results verifying proper system operation are also shown in that section. Depending on mode of operation, the PWM module creates one or more pulsewidth modulated signals, whose duty ratios can be independently adjusted. Implementation of PWM module in MCU Overview of the PWM module A block diagram of PWM module is shown in . It is clearly from the diagram that the whole module is posed of two sections: PWM signal generator and deadtime generator with channel select logic. The PWM function can be started by the user through implementing some instructions for initializing the PWM module. In particular, the following power and motion control applications are supported: ? DC Motor ? Uninterruptablel Power Supply (UPS) 仿真結(jié)果如圖 6 所示。 在單片機(jī)上執(zhí)行 PWM 模塊 PWM 模塊的概述 PWM 模塊如圖 3所示，從圖中，可以很清楚得看到整個(gè)模塊有兩部分組成： PWM信號(hào)產(chǎn)生器和帶有頻道選擇邏輯的死區(qū)時(shí)間產(chǎn)生器。 畢業(yè)設(shè)計(jì) (論文 )外文資料翻譯 學(xué) 院 ： 機(jī)械工程學(xué)院 專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 姓 名： 學(xué) 號(hào)： 1071101215 外文出處： Design of PWM Controller in a MCS51 Compatible MCU ( 用外文寫 ) 附 件： ； 。用戶可以通過執(zhí)行一些代碼使PWM模塊初始化，從而啟動(dòng)其功能。 Tr4 和 Tr3分別與 PWM0和 PWM1相連，實(shí)際上，從圖看，單片機(jī)的 P1[5]/P[4]口被用做 PWMH/PWML或是一般的 I/O 口。The PWM module also has the following features: ? Two PWM signal outputs with plementary or independent operation ? Hardware deadtime generators for plementary mode ? Duty cycle updates are configurable to be immediated or synchronized to the PWM Architecture of PWM Module Details of the architecture PMW generator The archite