Fax Modem Data Pump
For Fixed-Point DSPs
by Dallas Signal Processing, Inc.

Software Overview

The Dallas Signal Processing FAX-C25 is a DSP-based FAX transmitter and receiver algorithm that 
implements the CCITT notes V.29, V.27ter, and V.21. The software implements all the functions of a 
fax modem chipset. It may be used with digital lines (T1) or with an analog front end (codec and 
DAA). The code is a hardware-independent callable routine with an interface similar to that of a 
fax modem chip.

Features and Benefits

•	9600, 7200, 4800, 2400, and 300 bps
•	Field tested with most fax machines and line qualities
•	Field tested over United States and international lines
•	Software is structured and easy to install

Processor and System Specifications

•	Devices supported: TMS320C2x, TMS320C5x

Usage Limitations or Performance Considerations

•	Algorithm category: Telecommunications
•	Program memory usage: 7000 words
•	Data memory usage: 512 words
•	Processor loading: 45% in receive mode, 25% in transmit mode (`C5x)

Algorithm Verification

•	Fully implements the CCITT V.29, V.27ter, and V.21
•	Operation over 3002 worst-case lines

Availability

•	Available now

Company Background and Contact Information

Dallas Signal Processing is a small company specializing in DSP-based modem software. Our products 
include data as well as fax modems for TI's fixed-point and floating-point processors.

Contact:	Talal Itani
		Dallas Signal Processing, Inc.
		4112 Cassandra Lane
		Plano, Texas  75093
		(214) 867-1739
		(214) 867-5683