'C' Language FSK Modems: Bell 103, V.21 , V.23

Software Overview

ILLICO is offering 'C' language Digital Signal Processing software for the popular low speed FSK (frequency shift keyed) modem standards. These software modems can replace conventional data modem chip sets in applications where a general purpose DSP is available on a dedicated or shared basis. The modem software uses only fixed point (integer) multiplies and requires no special math library. Versions are available to support both conventional character oriented (asynchronous) format and the synchronous format normally used with HDLC protocols.

The 'C' language FSK modem software can be compiled for immediate operation on any processor. The software can also serve as a reference model for translation to highly efficient assembly language versions. All offered code was created by ILLICO staff and can be customized to support special interfaces and special signal processing requirements. 

Available Modems

  • Bell 103, full duplex 300bps.
  • V.21, full duplex 300 bps
  • V.23, full duplex 1200bps or 600bps in the forward direction, 75 bps in the reverse direction.

Target Applications

  • Telematics. 
  • Embedded communications for remote instrumentation. 
  • Remote network control. 
  • Caller I.D. (V.23)

Features and Benefits

  • ANSI standard 'C' language software for compilation on any processor.
  • Requires no special math library. 
  • Versions available for either asynchronous or synchronous line signal format.
  • Compatible with ILLICO's 'C' language HDLC coder/decoder product. 
  • Uses 'C' data structures for easy creation of multiple channels on one processor.
  • Block oriented I/O to facilitate processor sharing with other applications. 
  • Answer tone generation.
  • Diagnostic received power read-out.
  • Thirty page User's Guide to aid installation and application creation.

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