Home
Modems
Telephony
Audio
Utilities
Consultancy
Glossary
Index
Contact us

Exchange Tone Detector DSP C Code

Description: the AlgoTron Exchange Tone Detector (ETD) C code is for tones such as dial-tone and busy tone that emanate from standard PSTN telephone exchanges. The ETD determines on a sample-by-sample basis whether exchange tone(s) are present or not, leaving the user to monitor for tone cadences if needed eg for busy tone. Because of the variety of tone signals in different countries, a measure of programmability is given to the user. The corner frequencies of the band-pass can be selected from a family of filters.
        The C code is suitable for any processor with an ANSI-compliant C compiler. It is designed especially for efficient operation on low-cost fixed-point DSP- and general-purpose micro-processors. All data memory is specified as 16-bit integer words. Multiplies are integer 16x16-bit with 32-bit products.
        The software is organised in callable subroutines: a main routine for accepting samples suitable for multiple channels, and an initialisation routine for setting per-channel memory. Operation can be set for sample rates of 8.0kHz or 9.6kHz.

Processor Load:

- #example figures from compiling for the TI TMS320C5000(C55x) DSP processor at 8.0kHz sampling

Availability: NOW - sale is under licence - integration support offered