DATA BULLETIN
MX429A
Features
Band III & General Purpose Trunked Radio
Apps
Full-Duplex 1200 and 2400 Baud Operation
Error Check Word Generation and Checking
Preamble Generation
µProcessor Compatible Interface
CARRIER DETECT
TIME CONSTANT
RECEIVER INPUT
DATA
1200/2400bps MSK Modem
for Trunked Radio Systems
Frame SYNC and SYNT
Detection
Low Power Consumption
General Purpose Timer
RX MESSAGE FORMAT
MSK
RECEIVER
SYNC/SYNT
DETECTOR
BYTE
COUNTER
CHECKSUM
CHECKER
RX CHECKSUM TRUE
STATUS
REGISTER
SYNC
SYNT
RX DATA READY
1200/2400 BAUD
MICROPROCESSOR
INTERFACE
STROBE
RX CARRIER
DATA
DETECT
R/W
A1
A0
D7
D6
8-BIT uP BUS
D5
D4
D3
D2
D1
D0
V
BIAS
V
SS
V
DD
XTAL/CLOCK
XTAL
CLOCK
GENERATORS
1.008 MHz
OUTPUT
CLOCKS
RECOVERED CLOCK
RX DATA
REGISTER
8-BIT uP BUS
RX DATA
BUFFER
RX CARRIER DET.
RX CHECKSUM TRUE
TX DATA READY
TX IDLE
TX DATA
BUFFER
TIMER EXPIRED
CONTROL
REGISTER
RX ENABLE
TX ENABLE
RX MESSAGE FORMAT
TX PARITY ENABLE
CHECKSUM
GENERATOR
TX DATA
REGISTER
MSK
TRANSMITTER
BYTE
COUNTER
TX PARITY
ENABLE
TRANSMITTER
OUTPUT
TIMER
RX DATA RDY
TX DATA RDY
SYNC
SYNT
TX IDLE
INTERRUPT IRQ
GENERATOR
The MX429A is a single-chip CMOS 1200 and 2400 baud MSK modem, designed primarily for use in Trunked
Radio Systems but may also be employed in other general purpose radio or line data communication
applications. The device has been designed to conform to the UK Band III trunked radio protocols MPT
1317/1327.
The MX429A is full duplex at 1200 and 2400 baud and includes an 8-bit parallel microprocessor interface and
a programmable timer which may be set for interrupt periods of 8 to 120 bits. Preamble may be generated by
the device in transmit. The 16-bit SYNC or SYNT words are detected in receive. An error check word is
automatically generated in transmit and error checking is performed in the receive mode. An on-chip
Xtal/clock generator requiring an external 4.032MHz Xtal or clock input provides both 4.032MHz and
1.008MHz outputs and performs all modem timings.
The MX429A requires a single 5-volt power supply, has a powersave facility, and is available in the following
package styles: 24-pin CDIP (MX429AJ), 24-pin PDIP (MX429AP), and 24-pin PLCC (MX429ALH).
© 1998 MX-COM Inc.
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
www.mxcom.com Tel: 800 638-5577 336 744-5050
All trademarks and service marks are held by their respective companies.
Fax: 336 744-5054
Doc. # 20480128.007
CMLMICRO [ CML MICROCIRCUITS ]
