Digital Voice Systems VC-20-ATC-10B Especificaciones descargar pdf (Pagina 23)

FAA20 Embedded NEXCOM Vocoder

Board Manual

This manual has been prepared for the Federal Aviation Administration.

FA100-00107 (March 2004) – Rev 1.0.0 Page 17

5.0 FUNCTIONAL DESCRIPTION

This section provides a functional overview of the FAA20. The following

topics are included:

• Operational Modes. Discusses the normal operational mode and

three other optional modes.

• Interfaces. Discusses details for each of the three external voice

port types: the audio interface, the digital PCM interface and the

nibble interface. Interface timing diagrams are provided.

• Voice Processing. Presents the overall voice flow block diagram and

describes major blocks/functions in the flow.

• System Timing and Control. Discusses truncated timing mode, voice

delays, programmable LEDs and the command processor.

5.1 Operational Modes

The FAA20 supports four operational modes. The differences between

modes lie in how the FAA20 routes data and handles vocoder control

signals.

5.1.1 NORM Mode

The NORM mode is used for most FAA20 embedded applications. It

supports the expanded nibble interface and allows flexible routing and voice

signal level adjustments.

5.1.2 VC20 Mode

The VC20 mode is designed to allow the FAA20 to be used with minimal

effort for applications that have been developed based on the VC20. In this

mode, the expanded FAA20 features are disabled and some of the

configuration parameters are forced to a known state, i.e. flash settings are

ignored. Figure 4 provides a summary of the VC20 forced configuration

parameters.

1 2 ... 18 19 20 21 22 23 24 25 26 27 28 ... 108 109

Sin comentarios

Digital Voice Systems VC-20-ATC-10B Especificaciones Pagina 23