4-Level FSK Modem Data Pump

Page 3 of 50

MX929B PRELIMINARY INFORMATION

©2001 MX-COM, INC.

www.mxcom.com Tel: 800 638 5577 336 744 5050

Fax: 336 744 5054

Doc. # 20480171.003

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA

All trademarks and service marks are held by their respective companies.

4.5.2.16

TIB: Transmit Intermediate Block ............................................................................... 21

4.5.2.17

TLB: Transmit Last Block ........................................................................................... 21

4.5.2.18

T4S: Transmit 4 Symbols ........................................................................................... 21

4.5.2.19

TSID: Transmit Station ID ............................................................................................ 22

4.5.2.20

RESET: Stop any current action................................................................................. 22

4.5.2.21

Task Timing................................................................................................................ 22

4.5.2.22

RRC Filter Delay......................................................................................................... 23

4.5.3

Control Register .................................................................................................................... 24

4.5.3.1

Control Register B7, B6: CKDIV - Clock Division Ratio.............................................. 24

4.5.3.2

Control Register B5, B4: FSTOL - Frame Sync Tolerance to Inexact Matches ......... 24

4.5.3.3

Control Register B3, B2: LEVRES - Level Measurement Modes ............................... 25

4.5.3.4

Control Register B1, B0: PLLBW - Phase-Locked Loop Bandwidth Modes............... 25

4.5.4

Mode Register....................................................................................................................... 26

4.5.4.1

Mode Register B7: IRQEN - IRQ Output Enable....................................................... 26

4.5.4.2

Mode Register B6: INVSYM - Invert Symbols ............................................................ 26

4.5.4.3

Mode Register B5:

RX

TX/

- Tx/Rx Mode.................................................................. 26

4.5.4.4

Mode Register B4: RXEYE - Show Rx Eye ................................................................ 27

4.5.4.5

Mode Register B3: PSAVE - Powersave.................................................................... 27

4.5.4.6

Mode Register B2: SSIEN - 'S' Symbol IRQ Enable .................................................. 27

4.5.4.7

Mode Register B1, B0: SSYM - 'S' Symbol To Be Transmitted................................. 27

4.5.5

Status Register ..................................................................................................................... 28

4.5.5.1

Status Register B7: IRQ - Interrupt Request .............................................................. 28

4.5.5.2

Status Register B6: BFREE - Data Block Buffer Free................................................ 28

4.5.5.3

Status Register B5: IBEMPTY - Interleave Buffer Empty........................................... 28

4.5.5.4

Status Register B4: DIBOVF - De-Interleave Buffer Overflow ................................... 29

4.5.5.5

Status Register B3: CRCERR - CRC Checksum Error.............................................. 29

4.5.5.6

Status Register B2: 'S' Symbol Ready........................................................................ 29

4.5.5.7

Status Register B1, B0: SVAL - Received 'S' Symbol Value...................................... 29

4.5.6

Data Quality Register ............................................................................................................ 29

4.6 CRC, FEC and Interleaving.............................................................................................. 30

4.6.1

Cyclic Redundancy Codes .................................................................................................... 30

4.6.1.1

CRC0.......................................................................................................................... 30

4.6.1.2

CRC1.......................................................................................................................... 30

4.6.1.3

CRC2.......................................................................................................................... 30

4.6.1.4

Forward Error Correction............................................................................................ 30

4.6.1.5

Interleaving ................................................................................................................. 31

4.7 Transmitted Symbol Shape.............................................................................................. 31