CMX885 Datasheet, PDF (1/69 Pages) CML Microcircuits – Programmable Voice Scrambler

CML Microcircuits
COMMUNICATION SEMICONDUCTORS
CMX885
Marine VHF Audio and
Signalling Processor
D/885/3 December 2010
Audio and Signalling Processing, DTMF, DSC/ATIS and NOAA
with Auxiliary Functions for use in Marine VHF Systems
Features
• Concurrent Audio/Signalling/Data Operations
• Complete Audio-band Processing:
o Selectable Audio Processing Order
o Pre and De-emphasis
o Selectable 2.55/3.0 kHz Filtering
o Limiter
• DSC/ATIS Modem for Marine Applications
• Programmable Voice Scrambler
• Inband Signalling: DTMF, NOAA NWR
• C-BUS Serial Interface to Host µController
• DTMF and Audio Tone Encoder/Decoder
• Small VQFN and LQFP Packages
• Dual Auxiliary ADC, 4 Multiplexed Inputs
• 4 x Auxiliary DACs
• Dual Programmable System Clock Outputs
• Tx Outputs for Single, Two-Point Modulation
• 3 x Analogue Inputs (Mic or Discriminator)
• Digital Gain Adjustment
• Default 3.6864MHz Xtal/Clock
• Flexible Powersave Modes
• Low-power 3.0V to 3.6V Operation
Audio Out
Mic Input
Auxiliary
Multiplexed
ADC Inputs
Host µC
IRQ
C-BUS
Reference Clock
3V to 3.6V Supply
System Clock 1
System Clock 2
CMX885
Marine VHF
Baseband Processor
Auxiliary
DACs
Modulator
Discriminator
Optional 2^nd Receiver
Discriminator
Tx Enable
Rx Enable
RF
(Rx/Tx)
RF
(Rx)
1 Brief Description
The CMX885 is a half-duplex, audio, signalling and data processing IC for use in Marine VHF radio
systems.
Comprehensive audio processing facilities include complete audio processing, filtering, pre- or de-
emphasis and frequency inversion scrambling. Signal routing and filtering is included to assist host µC
based signal encoding/decoding applications.
1200bps Digital Selcall (DSC) or Automatic Transmitter Identification System (ATIS) modem with protocol
support and NWR decoding are supported.
A DTMF encoder/decoder, a full complement of auxiliary ADCs and DACs and dual synthesised clock
outputs are included in this low power PMR processor. The device also has flexible powersaving modes
and is available in 48-pin VQFN and LQFP packages.
© 2010 CML Microsystems Plc