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Details, datasheet, quote on part number:MX909A
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Datasheet text preview:
COMMUNICATION SEMICONDUCTORS
MX909A
GMSK Modem Data Pump
PRELIMINARY INFORMATION · · · · Flexible Operating Modes Host ”C Interface Low Power 3.3V/5.0V Operation 24-Pin Small Form Package Option
DATA BULLETIN
· · · ·
GMSK Modulation RX or TX up to 19.2k bits/sec Full Data Packet Framing Mobitex„ Compatible „
RADIO
MODULATOR RF DISCRIMINATOR ANALOG RX ANALOG TX
MX909A
MODEM DATA PUMP
DATA AND CONTROL BUS
HOST ”C
SYSTEM APPLICATION PROCESSING
The MX909A is a low power CMOS device containing all of the baseband signal processing and Medium Access Control (MAC) protocol functions required for a high performance GMSK Wireless Packet Data Modem. The MX909A interfaces with a host ”C and radio modulation/demodulation circuits to deliver reliable two-way transfer of application data over a wireless link. The MX909A assembles application data received from the host ”C, adds forward error correction (FEC), and error detection (CRC) codes, time-spreads this data by interleaving (burst-error protection) and scrambles (randomizes) the bit pattern. After automatically adding bit and frame sync codewords, the data packet is converted into analog GMSK signals for modulating into the radio transmitter. In the receive mode, the MX909A performs the reverse function using the analog signals from the receivers discriminator. After error correction and removal of the packet overhead, the recovered application data is supplied to the host ”C. Any CRC detected residual uncorrected errors in the data will be flagged. Readout of the SNR value during receipt of a packet is also provided. The MX909A uses data block sizes and FEC/CRC algorithms compatible with the Mobitex„ Wide Area Network over-air standard. The format used is suitable for other private applications where the high-speed transfer of data over narrow-band wireless links is required. The MX909A is programmable to operate at standard bit-rates from a wide choice of XTAL/CLOCK frequencies. The MX909A may be used with a 3.0V to 5.5V power supply and is available in the following packages: 24-pin SSOP (MX909ADS), 24-pin SOIC (MX909ADW), 24-pin PLCC (MX909ALH), and 24-pin PDIP (MX909AP).
€2001 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480134.005
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
GMSK Modem Data Pump
Page 2 of 37
MX909A PRELIMINARY INFORMATION
CONTENTS
Section Page 1 Block Diagram ...... 3 2 Signal List .... 4 3 External Components ......... 5 4 General Description ............ 6
4.1 4.2 4.3 4.4 4.5 Description of Data Blocks .... 6 Modem - ”C Interaction......... 9 Data Formats ......... 9 The Programmer's View...... 11 CRC, FEC, Interleaving and Scrambling Information..... 22
5 Application.......... 24
5.1 5.2 5.3 5.4 5.5 Transmit Frame Example.... 24 Receive Frame Example..... 26 Clock Extraction and Level Measurement Systems....... 28 AC Coupling......... 30 Radio Performance ............. 31
6 Performance Specification ........ 32
6.1 6.2 Electrical Performance ........ 32 Packaging ............ 36
MX·COM, Inc. Reserves the right to change specifications at any time and without notice.
€2001 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480134.005
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
GMSK Modem Data Pump
Page 3 of 37
MX909A PRELIMINARY INFORMATION
1 Block Diagram
IRQ 8 D0 D1 D2 D3 D4 D5 D6 D7 WR RD CS A0 A1
VDD VDD
STATUS REGISTER
DATA QUALITY REGISTER
”CONTROLLER INTERFACE
DATA BUS BUFFERS
COMMAND REGISTER
MODE REGISTER
CONTROL REGISTER
DATA BUFFER
CRC GENERATOR/ CHECKER
ADDRESS AND R/W DECODE
FEC GENERATOR/ CHECKER
INTERLEAVE/ DE-INTERLEAVE
FRAME SYNC DETECT
VBIAS Tx Bits VSS SCRAMBLE/ DE-SCRAMBLE Rx Bits
RXAMPOUT Rx Input Amp VBIAS RXIN XTAL CLOCK OSCILLATOR AND DIVIDERS XTAL / CLOCK Rx
Tx LOW PASS FILTER Rx Tx Tx Rx
DOC1 Rx LEVEL/CLOCK EXTRACTION DOC2
TXOUT Tx Output Buffer
VBIAS
Figure 1: Block Diagram
€2001 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480134.005
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
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