目录绪论............................................................11系统设计..........................................................21.1方案论证......................................................21.1.1信号模块.................................................21.1.2控制模块.................................................31.1.3显示模块.................................................41.1.4键盘输入模块.............................................41.1.5系统各模块的最终方案.....................................41．2理论分析与计算..............................................51.2.1频率精度计算.............................................51.2.2DDS的理论分析............................................51.2.3DDS的参数计算............................................62硬件系统设计......................................................72．1硬件元器件的选用............................................72.1.1C8051F020控制芯片简介....................................72.1.2AD9954简介...............................................92．2单元硬件电路设计...........................................132.2.1矩阵(4×4)键盘电路......................................132.2.2电源电路................................................142.2.3电压调幅电路............................................142.2.4方波电路................................................142.2.5三角波电路...............................................153软件系统设计.....................................................163.1程序流程图..................................................164系统测试.........................................................194.1仿真测试.....................................................194.2指标测试.....................................................194.3测试方法......................................................205结束语...........................................................22致谢...............................................................23参考文献...........................................................24附录一对AD9954编程的主要源程序清单............................25附录二LCD显示子程序.............................................35摘要：随着数字集成电路、微电子技术和EDA技术的深入研究，DDS技术以其有别于其它频率合成技术的优越性能和特点，成为现代频率合成技术中的佼佼者。根据题目要求，我们以单片机C8051F020芯片和AD9954芯片为核心，辅以必要的模拟电路，设计一台信号发生器，使之能产生正弦波、方波和三角波。该系统主要由控制模块、信号模块、显示模块、键盘输入模块构成。仅用单片AD9954就实现了直接数字频率合成技术（DDS），产生稳幅正弦波。输出的正弦波经过比较电路来实现方波的输出，而三角波则是在方波的基础上通过接入积分电路来实现的。单片机对内部寄存器控制，AD9954就可以产生一个频谱纯净、频率和相位都可编程控制且稳定性很好的模拟波形，整个系统结构紧凑，电路简单，功能强大，可扩展性强。通过键盘输入、LCD显示形成人机交互界面，实现对输出信号的控制。关键词：信号发生器；C8051F020；直接数字频率合成器（DDS）；AD9954Abstract：Asdigitalintegratedcircuits,microelectronictechnologyandin-depthstudyofEDAtechnology,itstechnologyisdifferentfromotherDDSfrequencysynthesizertechnologyandthesuperiorperformancecharacteristicsofamodernfrequencysynthesistechnologyleader.Underthetitle,weC8051F020microcontrollerchipandAD9954chipasthecore,supplementedbythenecessarycircuitsimulation,designasignalgenerator,sothatitcanproducesine,squareandtriang...
