DTMF 编解码器在编码时将击键或数字信息转换成双音信号并发送,解码时在收到的DTMF 信号中检测击键或数字信息的存在性.采用ccs2.2开发。运行在DES5410APP-U开发版上。

子程序_start_ac01，完成AD 及DSP 的多通道缓冲串口（McBSP）初始化。

子程序_iir_to_dtmf，通过由函数set_freq_coff()初始化的系数，分别迭代运算产生行

频和列频，该子程序计算出的两个频率信号样本值分别放入累加器a 和b，相加之

后作为新的一个音频样本发送。

main.c 文件完成整个流程控制，包括实验系统初始化系列函数、延时函数

mydelay()、打印函数。-DTMF codec in the encoding of digital information when converting keystrokes or dual tone signal and send, decode received DTMF signals when the detected keystroke or the existence of digital information. Using ccs2.2 development. Run in DES5410APP-U development edition. Subroutine _start_ac01, complete the AD and DSP multi-channel buffered serial port (McBSP) initialization. Subroutine _iir_to_dtmf, by the function set_freq_coff () initialization of the coefficient, iterative produce the frequency and column frequency, the subroutine to calculate the value of the two frequency signals samples were placed in the accumulator a, and b, with increase after an audio sample as a new sent. main.c file to complete the process control, including the series of experimental system initialization function, delay function mydelay (), print function.