1200/2400bps MSK Modem for Trunked Radio Systems
2
MX429A
CONTENTS
Section
Page
1 Block Diagram................................................................................................................. 3
2 Signal List........................................................................................................................3
3 External Components.....................................................................................................5
4 General Description........................................................................................................6
4.1 Modems in Mobile Data Signaling.......................................................................................... 6
4.1.1 Digital Code Format....................................................................................................................6
4.1.2 Operation....................................................................................................................................6
4.1.3 Non MPT Application – Full-Duplex..........................................................................................7
4.1.4 Control Register (A1 = 1, A0 = 1, R/W = 0, Write Only)...........................................................7
4.1.5 Status Register (A1 = 1, A0 = 1, R/W = 1, Read Only)............................................................8
4.1.6 Rx Data Buffer (A1 = 1, A0 = 0, R/W = 1, Read Only).............................................................9
4.1.7 Tx Data Buffer (A1 = 1, A0 = 0, R/W = 0, Write Only)..............................................................9
4.2 Syndrome Word.................................................................................................................... 10
4.2.1 Syndrome Low Byte (A1 = 0, A0 = 0, R/W = 1, Read Only) ..................................................10
4.2.2 Syndrome High Byte (A1 = 0, A0 = 1, R/W = 1, Read Only)..................................................10
4.3 Carrier Detect Time Constant............................................................................................... 10
5 Application ....................................................................................................................11
5.1 Checksum Generation and Checking................................................................................... 11
5.2 Receive Operation................................................................................................................ 11
5.3 Transmit Operation............................................................................................................... 12
5.4 Basic Power Up Software..................................................................................................... 13
5.5 Basic Software Interrupt Flow............................................................................................... 14
5.6 Bus Interface Timing............................................................................................................. 15
5.6.1 Bus interface design migration from MX429 to MX429A..........................................................15
6 Performance Specification...........................................................................................15
6.1 Electrical Performance ......................................................................................................... 15
6.1.1 Absolute Maximum Ratings......................................................................................................15
6.1.2 Operating Limits .......................................................................................................................15
6.1.3 Operating Characteristics.........................................................................................................16
6.1.4 Timing.......................................................................................................................................18
6.2 Packaging............................................................................................................................. 18
MX•COM, Inc. reserves the right to change specifications at any time and without notice.
© 1998 MX-COM Inc.
www.mxcom.com Tel: 800 638-5577 336 744-5050 Fax: 336 744-5054
Doc. # 20480128.007
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
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CMLMICRO [ CML MICROCIRCUITS ]
