4-Level FSK Modem Data Pump
Page 2 of 47
MX919B PRELIMINARY INFORMATION
CONTENTS
Section
Page
1. Block Diagram ............................................................................................................... 6
2. Signal List ...................................................................................................................... 7
3. External Components ................................................................................................... 8
4. General Description ...................................................................................................... 9
4.1
Description of Blocks ......................................................................................................... 9
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.1.7
4.1.8
4.1.9
Data Bus Buffers..................................................................................................................... 9
Address and R/W Decode ...................................................................................................... 9
Status and Data Quality Registers.......................................................................................... 9
Command, Mode, and Control Registers ............................................................................... 9
Data Buffer.............................................................................................................................. 9
CRC Generator/Checker ........................................................................................................ 9
FEC Generator/Checker ......................................................................................................... 9
Interleave/De-Interleave Buffer............................................................................................... 9
Frame Sync Detect ................................................................................................................. 9
4.1.10 Rx Input Amp ........................................................................................................................ 10
4.1.11 RRC Low Pass Filter ............................................................................................................ 10
4.1.12 Tx Output Buffer.................................................................................................................... 11
4.1.13 Rx Level/Clock Extraction..................................................................................................... 12
4.1.14 Clock Oscillator and Dividers................................................................................................ 12
4.2
4.3
4.4
4.5
Modem - µC Interaction ................................................................................................... 12
Binary to Symbol Translation ........................................................................................... 13
Frame Structure............................................................................................................... 14
The Programmer’s View................................................................................................... 15
4.5.1
4.5.2
Data Block Buffer .................................................................................................................. 15
Command Register ............................................................................................................... 15
Command Register B7: AQSC - Acquire Symbol Clock ................................................ 16
Command Register B6: AQLEV - Acquire Receive Signal Levels ................................. 16
Command Register B5: CRC ........................................................................................ 16
Command Register B4: TXIMP - Tx Level/Impulse Shape ............................................ 16
Command Register B3 - Reserved ................................................................................ 16
Command Register B2, B1, B0: TASK........................................................................... 16
NULL: No effect .............................................................................................................. 18
SFSH: Search for Frame Sync plus Header Block ........................................................ 18
RHB: Read Header Block............................................................................................... 18
4.5.2.1
4.5.2.2
4.5.2.3
4.5.2.4
4.5.2.5
4.5.2.6
4.5.2.7
4.5.2.8
4.5.2.9
4.5.2.10 RILB: Read 'Intermediate' or 'Last' Block ....................................................................... 18
4.5.2.11 SFS: Search for Frame Sync ......................................................................................... 18
4.5.2.12 R4S: Read 4 Symbols .................................................................................................... 19
4.5.2.13 T24S: Transmit 24 Symbols ........................................................................................... 19
4.5.2.14 THB: Transmit Header Block.......................................................................................... 19
4.5.2.15 TIB: Transmit Intermediate Block ................................................................................... 20
4.5.2.16 TLB: Transmit Last Block ............................................................................................... 20
©2001 MX•COM, INC.
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Doc. # 20480170.003
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