Codec PC104

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• Overview
• Feature Summary
• Applications
• User-Interface Panel
• Bit Packing
• Board Pictures
• User Manual
• Codec PC Simulation
• MELPe Speech Codecs

Overview

The Codec PC104 is a small-form factor, DSP-based platform for high compression rate voice encoding. It can be used as both a development system and production board due to its PC104 compliance.  In development system mode, the Codec-PC104 supports development of application-specific DSP software and host processor software and provides evaluation and measurement tools.  The Codec-PC104 can then be migrated to production and deployment with little or no modification.

Features

• Includes SigC5x-PC104 board, SigC5416 DSP module, SigSD4 4-channel audio module optional RS-422, 10/100 Ethernet, and RS-232 interface
• Configurable with "demo licenses" for a variety of low bitrate (LBR) codecs (see table below)
• Operates in both stand alone mode (using HESC-104 or similar power board and external A/C adapter wall plug), or  insertable into WinXP or Linux PC

Stand Alone Codec-PC104 Demo/Development Board Set

The above figure shows the Codec-PC104 board in stand-alone mode, mounted on a power board. The AC adapter connection is visible along the left edge of the power board. AC adapters for Europe, Asia and North/South America are available.

Applications

• Size-constrained and/or power-constrained applications, for example UAV (unmanned aerial vehicle), shipboard, automotive
• Systems that require signal processing capabilities
• Systems that utilize Texas Instruments licenses and other TI patent porfolio software
• Test equipment and lab bench measurement for voice communications systems

User Interface Panel

Codec-PC104 Board “Mode” Switch Positions				Codec-PC104 Board “Bit Packing” Switch Positions
Position	Function	Comments		Position	Function
0	G726 16 kbps	ITU bit-exact		2	54-bit /81-bit byte-packed format
1	CVSD 16 kbps	Includes FIR shaping filters		Other	Unpacked format (see notes in “Bit Packing” description below)
2	Audio Loopback	16-bit PCM
3	MELPe 2400 bps	STANAG 4591 bit exact
4	CVSD 32 kbps	Includes FIR shaping filters
5	MELPe 600 bps	Signalogic MELPe-Plus
6	MELPe 1200 bps	STANAG 4591 bit-exact
7	G726 32 kbps	ITU bit-exact

Bit Packing

Digital transmission of compressed data over RS-422 or 10/100 Ethernet may be in "packed" or "unpacked" formats.
• Byte-packed and 2-bit and 4-bit unpacked formats for CVSD and G726
• 54-bit packed format for MELPe 2400 bps, 81-bit packed format for MELPe 1200 bps or 108-bit format for MELPe-Plus 600 bps
• 9 byte unpacked format for MELPe 2400 bps (9 6-bit coefficients), 14-byte unpacked format for MELPe 1200 bps (13 6-bit coeeficients and 1 3-bit coefficient), or 18-byte unpacked format for MELPe-Plus 600 bps (18 6-bit coefficients)

Board Pictures

Codec-PC104 Board Switches and Indicators, Top View