基于FPGA/MCU多功能信号发生器的设计与实现

Design and implementation of multi-function signal generator based on FPGA/MCU

针对采用直接数字式频率合成(DDS)芯片无法直接产生多种信号波形的情况,提出基于现场可编程门阵列(FPGA)和高速微处理器(MCU)构建DDS技术,实现多功能高精度信号发生器的设计方案。发生器主要由基于FPGA的DDS电路、MCU控制、DAC、增益可控放大器(VGA)、功率放大(PA)、低通滤波器(LPF)、人机接口、系统时钟及电源等电路组成。MCU选用C8051F020芯片,它主要负责与外界的接口及系统控制。多功能信号发生器软件设计采用QuartusⅡ和Keilμv3开发软件,用VHDL和C语言编程实现,给出了系统软件主控流程图。所设计的多功能信号发生器可产生正弦波、方波和三角波,测试表明各项参数性能优于技术指标。

As DDS（Digital Frequency Synthesizer） chips are unable to generate different kinds of signal waveform directly, it is proposed to construct DDS technique with FPGA（Field Programmable Gate Array） and high speed MCU（Micro Controller Unit） and design the multi-function high-precision signal generator. The generator is mainly composed of the FPGA-based DDS,MCU controller,DAC,VGA（Variable Gain Amplifier）, PA （Power Amplifier）, LPF（Low- Pass Filter）, MMI, system clock and power supply. MCU C8051F020 is mainly responsible for interfacing with outside and system control. Its software design applies Quartus 1I and Keillxv3 developing software and is programmed with VHDL and C language. The flowchart of system master control is given. The designed multi-function signal generator generates sine, square and triangle waves. Tests show that the performance is better than the technical parameters.