摘要
本文主要介绍了CCITT G.722建议的编译码器的硬件实现,以及利用低速EPROM与高速RAM替代高速PROM的方法.在系统不增加额外的管理控制CPU的情况下,将低速EPROM内的汇编码字分别写到编码器和译码器的高速RAM内.在不引起编译码系统混乱的前提下,将时钟由低切换到高.
This paper describes an implementation for the CCITT G.722 codec in the DSP chip of TMS32010 and a method employing low spced EPROM and high speed RAM(access time<70ns)instead of high speed PROM.when the codec is powered on,the data of assembly codes in EPROM will be read and simulta- neously written,in the low timing clock of 5 MHz,to encoder RAM and decoder RAM respectively.No extra CPU is needed for controlling of reading data from EPROM and writing the data to RAMs.The clock cutover will happen when the reading and writing are finished,then the codec works in the high timing clock of 20 MHz.
基金
国家自然科学基金
关键词
音频信号
编译码器
硬件
wideband audio signals codec
sub-band coding
ADPCM
clock cutover
