Audio Signaling Processor

8

MX803A PRELIMINARY INFORMATION

© 1996 MX•COM, INC.

Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054

Doc. # 20480122.003

4.2.3 MX805A Sub-Audio Signaling Processor

This provides a sub-audio and digital signaling (NRZ) ability to LMR and other Radio Systems.

4.2.4 MX806A Audio Processor

This is a half duplex audio processor providing all DBS800 system audio signal conditioning and filtering capabilities for

the system transmit and receive paths.

4.2.5 MX809 MSK Modem

This is an intelligent, half-duplex 1200bps MSK/FFSK Modem with software programmable byte-synchronization system

and checksum generation and checking.

4.2.6 MX812 VSR Codec

This is a half-duplex CVSD speech encoder/decoder with the ability to store and retrieve data within attached DRAM

(Dynamic Random Access Memory) using an on-chip DRAM controller

4.3 C-BUS Control

C-BUS is the controlling hardware and software interface for all members of the DBS800 family. It enables the serial, bi-

directional transfer of commands and data throughout the system, allowing total flexibility of operational control and data

handling. System upgrades can be achieved by a simple software or firmware change.

The C-BUS physically consist of 5 lines. These lines are Serial Clock, Command Data, Reply Data, Chip Select ( CS ),

and Interrupt Request ( IRQ ). A description of each may be found in section 2.

5. Application

Control of the MX803A Audio Signaling Processor's operation is by communication between the

µC and the MX803A

internal registers on the C-BUS using Address/Commands (A/Cs) and appended instructions or data. See Figure 8. The

use and content of these instructions is detailed in the following sections.

For additional application information contact MX

•COM, Inc.

5.1 MX803A Internal Registers

Control Register

Write only, control and configuration of the MX803A.

Status Register

Read only, reporting of device functions.

RX Tone Frequency Register

Read only, indicates frequency of the last received input.

RX Notone Timer

Write only, setting of the RX Notone period.

TX Tone Generator 1 Register

Write only, setting the required output frequency from TX Tone Generator 1.

TX Tone Generator 2 Register

Write only, setting the required output frequency from TX Tone Generator 2.

General Purpose Timer Register

Write only, setting of a general purpose sequential time period.