基于AT89S52和K9F6408UOA的语音数字系统设计

在研究传统语音录放电路的基础上，提出了一种基于AT89S52的音频信号采集、存储与处理系统。该系统以单片机AT89S52为控制器，采用键盘和LCD作为人机界面，ADC0809采集音频信号，扩展8MB闪速存储器K9F6408UOA作为数字化音频信号的存储器，通过软件滤波滤除噪音；采用PWM产生声音的原理，使存储在Flash中的音频数据控制PWM每个波形的占空比，通过低通滤波器将声音从PWM的脉冲中分离，并驱动扬声器。实验表明：8kHz采样频率和8位采样位数可获得清晰的语音以及较好的音乐声，语音存储时间达15min。

Design of digital voice system based on AT89S52 and K9F6408UOA

Based on the research of traditional speech recorders circuit, this paper proposed a AT89S52-based audio signal acquisition, storage and processing system. The system design used MCU AT89S52 as a controller, the keyboard and the LCD for man-machine interface, and ADC0809 for audio signals acquisition. The design extended 8MB flash memory K9F6408UOA as digital audio signal memory, and filtered out the noise by software filtering. The design used the principle of PWM sound generating, and made the audio data stored in the Flash to control the PWM duty cycle of each waveform. Through low-pass filter, the sound was separated fi＇om the PWM pulse, and drove the speaker. Experimental results show a clear voice and good music could be got by using 8kHz sampling fi＇equency and 8-bit sampling bits. Voice storage time is up to 15 minutes.