Multifrequency Tone Detection
by D2 Technologies, Inc.

Software Overview

D2's Multifrequency (MF) Tone Detection algorithm module detects the presence of all R1 and R2 MF 
tones, as well as the R1 and R2 signaling tones under a broad range of network conditions and under 
international telecommunications specifications.
Designed to the VP Open interface, the Multifrequency Tone Detection module easily integrates with 
other VP Open modules, runs in real-time concurrently with other VP Open modules, and handles any 
number of voice ports assigned to the DSP. Like all of D2's algorithm modules, MF Tone Detection 
consists of robust software that is rigorously tested.

Features and Benefits

•	Detects the presence of all 15 R1 Multifrequency signals
•	Detects leading and trailing edge
•	Detects the presence of all 15 R2 Forwards and 15 R2 Backwards Multifrequency signals
•	Accepts telephone-band codec or linear data
•	Detects the line signaling tones for both R1 and R2 signaling

Processor and System Specifications

•	Devices supported: TMS320C2xx, TMS320C3x, TMS320C5x
•	Processor resource required:
•	Algorithm category: Telecommunications
TMS320C2xx (Est.)
TMS320C3x (Est.)
TMS320C5x (Est.)
Program memory
1.1 kwords
0.6 kwords
1 kwords
Data memory/port
45 words
40 words
45 words
Processor loading
worst case
1.4 MIPS
0.85 MIPS
1.20 MIPS

Usage Limitations or Performance Considerations

•	The host, voice data input and output, memory allocation, and module to module communication 
interfaces must conform to VP Open as described in the VP Open Software Interface Specification.

Algorithm Verification

D2's Multifrequency Tone Detection algorithm module is validated through the following suite of 
tests:
•	D2's R1,R2 detection tests for tone duration, tone frequency shift and twist, signal to noise, 
and tone levels
•	VP Open interface validation – module is integrated with other VP Open modules and tested 
concurrently in real-time on the D2 VDS50 system for multiple voice ports

Availability

Will be available for the TMS320C5x 1Q 1996. Implementation for the TMS320C2xx and the TMS320C3x 
and a demonstration package for the TI EVM50 DSP board will be available 2Q 1996.

Company Background and Contact Information

D2 Technologies, Inc. was founded by David Y. Wong and David M. Lindsay to help companies innovate 
telecommunications and information products with voice processing technology, which include 
telephony and voice algorithms, real-time system software, and development services.
With over 20 years of experience in voice processing algorithms, real-time DSP implementation, 
real-time systems, telephone systems, and voice processing applications, D2's business model is to 
develop close partnerships with its customers via high levels of service and special engineering to 
ensure mutual success.
Contact:	D2 Technologies, Inc.
		Attn:  Product Sales
		104 West Anapamu Street, Suite J
		Santa Barbara,  CA 93101
		(805) 564-3424
		Fax:  (805) 966-2144
		e-mail:  sales@d2tech.com