DTMF

DTMF (Dual Tone Multiple Frequency) signaling system is used for touch-tone dialing. Each of the 16 digits are signified by pairs of tones, one from a "low" group - 697Hz, 770Hz, 852Hz, 941Hz - and the other from a "high" group - 1209Hz, 1336Hz, 1477Hz, 1633Hz. DTMF receivers detect the presence of these tones, while eliminating background noise and allowing for distortions introduced by the network.

Technical Specification

• Supports generation and detection of 16 DTMF digits
• Conformance to ITU Q.23 and Q.24 standards
• Configurable frame length
• Configurable parameters (power level , power twist and the on-off duration of the lower and higher frequencies)
• Multi Channel, Reentrant implementation
• C callable API for initialization, decoding of all three layers
• Optimized implementation

Applications

• Telecommunications (public or private telephone exchanges; telephony and line test equipment)
• Voice Mails , Voice Response Systems
• Remote control of computer and telephone equipment

Platforms

• Currently supported on TI C54x™ (TMS320C54xx™)
• Plan to support on TI C64x™ (TMS320C64xx™)
• For other platforms contact mkt@ittiam.com