R2
Transceiver
by DNA Enterprises, Inc.

Software Overview

DNA Enterprises' R2 Transceiver package provides a multi-channel R2 generator and receiver. The 
number of channels is configurable at compile time. Each transmit channel is individually 
configurable to transmit forward or backward tones, as is each receive channel. This package is 
developed for the TMS320C3x digital signal processor. R2 signals are generated and detected as 
specified by ITU-T Recommendations Q.454 and Q.455.
The software's modular design separates signal detection and generation issues from data I/O and 
command I/O issues. This allows the R2 software to "bolt" into custom hardware platforms. Data 
memory requirements for this algorithm are based on the number of channels configured. Less data 
memory is used if fewer channels are required.

Features and Benefits

•	Simultaneously generates and detects R2 on up to 30 channels 
•	Modular design allows custom I/O development
•	Transmits/detects tones according to ITU-T Recommendations Q.454, Q.455
•	Number of channels is configurable
•	Supports stack or register parameter passing

Processor and System Requirements

Target processor:
TMS320C3x DSP
Algorithm category:
Telecommunications
Program memory usage:
385 words
Data memory usage:
585 words (based on 30 channels)
Transmitter processor loading:
0.119 MIPS (per channel)
Receiver processor loading: 
0.344 MIPS (per channel)
Data coding format:
13-bit linear PCM at 8 kHz

Algorithm Verification

DNA Enterprises' R2 algorithm was validated on a third-party PC plug-in board using a 33-MHz 
TMS320C3x according to  ITU-T Recommendations Q.454 and Q.455.  The following receiver tests (for 
both forward-mode and backward-mode tones unless otherwise indicated) were included in the test 
suite:
•	R2 tone type-A detection
•	R2 tone type-B detection
•	R2 tone rejection due to low levels
•	R2 tone detection in the presence of low- power disturbing frequencies
•	R2 tone detection in the presence of forward tones
•	R2 tone rejection in the presence of 
-38.5 dBm0 disturbing tone, forward mode
•	R2 tone rejection in the presence of 
-5 dBm0 disturbing tones
•	R2 tone rejection due to large twists

•	Available now on the TMS320C3x DSP
•	Licensable in object or source-code format

Availability

DNA Enterprises offers consulting services to tailor the R2 Transceiver software package to your 
specific needs. This includes porting the algorithm to another Texas Instruments DSP.

Company Background and Contact Information

DNA Enterprises Inc. specializes in telecommunication and real-time multiprocessor embedded 
systems. We provide turnkey design and development, offering software, hardware, and digital signal 
processing expertise for all project phases.

Contact:	Mr. Brian Berger
		269 West Renner Parkway
		Richardson, Texas  75080
		(214) 644-3301
		Fax: (214) 644-6338
		e-mail: info@dna.metronet.com