AIS Baseband IC with/without RF Synthesiser
CMX7032/CMX7042
6
General Description
6.1 Overview
Tx Modem Functions
AIS 25kHz channel (GMSK, 9600bps, 2.4kHz deviation, BT = 0.4)
AIS Burst mode with full AIS frame formatting (HDLC-type)
o
o
o
o
Bit stuffing
NRZI coding
Training sequence and start/stop flag insertion
CRC generation
AIS Raw mode (for greater flexibility)
Supports arbitrary data streams for user-defined protocols
o
Full support for the AIS Class B carrier-sensing channel access scheme (CSTDMA)
Full support for the AIS Class B Self-organising TDMA access scheme
160 byte (equivalent to 5 AIS slots) Tx data buffer
Flexible Tx Interface
o
o
Two-point modulation outputs, with independent gain and polarity controls
I/Q modulation outputs, for use with an I/Q upconverter
CS-SYNC output to facilitate IEC 62287-1 testing
Rx Modem Functions
Configurable modulation format:
o
o
AIS 25kHz channel (GMSK, 9600bps, 2.4kHz deviation, BT = 0.4)
DSC (de-emphasised FSK, 1200bps)
Simultaneous reception of two AIS channels, or one AIS and one DSC channel
AIS Burst mode with full AIS frame formatting (HDLC-type)
o
o
o
o
o
Frame sync recognition
Bit de-stuffing
NRZI decoding
Training sequence and start/stop flag detection
CRC checking
AIS Raw mode (for greater flexibility)
Supports arbitrary data streams for user-defined protocols
DSC reception
o
o
o
Raw mode
Formatted mode
Four 160-byte Rx data buffers can automatically store up to four 5-slot AIS bursts (2 per Rx
channel)
Rx signal input gain and polarity controls
Time-of-arrival reporting assists with timekeeping in the absence of GPS
Option to report messages with CRC errors
100 - 600 MHz RF Synthesisers (CMX7032 only)
Two Integer-N synthesisers
Flexible design minimises reference spurs for low phase noise results
Charge pump
o
o
High/low soft selectable current setting to speed large frequency channel changes
Nominal current user defined by external resistor value
Lock detect
2012 CML Microsystems Plc
17
D/7032/42_FI1.2/13
CMLMICRO [ CML MICROCIRCUITS ]
