多通道可编程声音发生器的设计

Design of Multi-Channel Programmable Sound Generator

针对消费性电子产品对声音处理单元APU(Audio Process Unit)的需要,设计了5通道的可编程声音发生器PSG(Programmable Sound Generator),可提供4个模拟声道和1个PCM(Pulse Code Modulation)数字通道。可同时产生高频乐音,低频乐音,还可以播放增量脉冲编码调制方式编码的语音信号,并具有振幅、频率可自动调整,方波占空比可以设定,声道定时关闭等多种特性。五个通道之间是并行的,每个端口寄存器都分配有自己的地址,其参数的设置不会影响其他通道。该PSG已用于家庭娱乐和学习系统中,并通过了FPGA验证,应用测试结果表明其性能达到设计要求。

The PSG with five channels is presented, which has four analog channels and one PCM digital channel. It can produce high and low frequency music and the DPCM voice signal,and has some characteristics such as volume envelope, frequency sweep abilities,output duty cycle adjustment and sound channel timing shutdown. Besides, the five channels are parallel and every port register has its own address which parameter value has no effect on others. The PSG has been used in family amusement and in study system, It has realized FPGA confirmatory test. The results show that the performance reaches the demand of design.