XRT73LC00A_08 Datasheet, PDF (6/63 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT

REV. 1.0.1
XRT73LC00A
E3/DS3/STS-1 LINE INTERFACE UNIT
3.1 INTERFACING THE RECEIVE SECTION OF THE XRT73LC00A TO THE LINE ......................................... 31
FIGURE 17. RECOMMENDED SCHEMATIC FOR INTERFACING THE RECEIVE SECTION OF THE XRT73LC00A TO THE LINE (TRANSFORMER-
COUPLING)..................................................................................................................................................................... 31
FIGURE 18. RECOMMENDED SCHEMATIC FOR INTERFACING THE RECEIVE SECTION OF THE XRT73LC00A TO THE LINE (CAPACITIVE-COU-
PLING)............................................................................................................................................................................ 32
3.2 THE RECEIVE EQUALIZER BLOCK ............................................................................................................. 32
3.2.1 GUIDELINES FOR SETTING THE RECEIVE EQUALIZER ....................................................................................... 32
FIGURE 19. THE TYPICAL APPLICATION FOR THE SYSTEM INSTALLER ............................................................................................. 33
COMMAND REGISTER CR2 (ADDRESS = 0X02)............................................................................................. 34
3.3 PEAK DETECTOR AND SLICER ................................................................................................................... 34
3.4 CLOCK RECOVERY PLL ............................................................................................................................... 34
3.5 THE HDB3/B3ZS DECODER ......................................................................................................................... 35
3.5.1 B3ZS DECODING DS3/STS-1 APPLICATIONS ........................................................................................................ 35
FIGURE 20. AN EXAMPLE OF B3ZS DECODING ............................................................................................................................... 35
3.5.2 HDB3 DECODING E3 APPLICATIONS...................................................................................................................... 35
FIGURE 21. AN EXAMPLE OF HDB3 DECODING .............................................................................................................................. 36
3.5.3 ENABLING/DISABLING THE HDB3/B3ZS DECODER ............................................................................................. 36
COMMAND REGISTER CR2 (ADDRESS = 0X02)............................................................................................. 36
3.6 LOS DECLARATION/CLEARANCE .............................................................................................................. 36
3.6.1 THE LOS DECLARATION/CLEARANCE CRITERIA FOR E3 APPLICATIONS....................................................... 37
FIGURE 22. THE SIGNAL LEVELS THAT THE XRT73LC00A DECLARES AND CLEARS LOS (E3 MODE ONLY)..................................... 37
FIGURE 23. THE BEHAVIOR OF THE LOS OUTPUT INDICATOR IN RESPONSE TO THE LOSS OF SIGNAL AND THE RESTORATION OF SIGNAL
38
3.6.2 THE LOS DECLARATION/CLEARANCE CRITERIA FOR DS3 AND STS-1 APPLICATIONS ................................ 38
TABLE 4: THE ALOS (ANALOG LOS) DECLARE AND CLEAR THRESHOLDS FOR A GIVEN SETTING OF LOSTHR AND REQEN FOR DS3 AND
STS-1 APPLICATIONS ..................................................................................................................................................... 38
COMMAND REGISTER CR0 (ADDRESS = 0X00)............................................................................................. 39
COMMAND REGISTER CR2 (ADDRESS = 0X02)............................................................................................. 39
COMMAND REGISTER CR0 (ADDRESS = 0X00)............................................................................................. 39
COMMAND REGISTER CR2 (ADDRESS = 0X02)............................................................................................. 40
3.6.3 MUTING THE RECOVERED DATA WHILE THE LOS IS BEING DECLARED......................................................... 40
COMMAND REGISTER CR3 (ADDRESS = 0X03)............................................................................................. 40
3.7 ROUTING THE RECOVERED TIMING AND DATA INFORMATION TO THE RECEIVING TERMINAL EQUIP-
MENT .............................................................................................................................................................. 40
FIGURE 24. THE TYPICAL INTERFACE FOR THE TRANSMISSION OF DATA IN A DUAL-RAIL FORMAT FROM THE RECEIVE SECTION OF THE
XRT73LC00A TO THE RECEIVING TERMINAL EQUIPMENT................................................................................................ 41
FIGURE 25. HOW THE XRT73LC00A OUTPUTS DATA ON THE RPOS AND RNEG OUTPUT PINS .................................................... 41
FIGURE 26. THE BEHAVIOR OF THE RPOS, RNEG AND RCLK1 SIGNALS WHEN RCLK1 IS INVERTED ............................................ 42
COMMAND REGISTER CR3 (ADDRESS = 0X03)............................................................................................. 42
3.7.1 ROUTING SINGLE-RAIL FORMAT DATA (BINARY DATA STREAM) TO THE RECEIVE TERMINAL EQUIPMENT 42
COMMAND REGISTER CR3 (ADDRESS = 0X03)............................................................................................. 42
FIGURE 27. THE TYPICAL INTERFACE FOR THE TRANSMISSION OF DATA IN A SINGLE-RAIL FORMAT FROM THE RECEIVE SECTION OF THE
XRT73LC00A TO THE RECEIVING TERMINAL EQUIPMENT................................................................................................ 43
FIGURE 28. THE BEHAVIOR OF THE RPOS AND RCLK1 OUTPUT SIGNALS WHILE THE XRT73LC00A IS TRANSMITTING SINGLE-RAIL DATA
TO THE RECEIVING TERMINAL EQUIPMENT ....................................................................................................................... 43
4.0 DIAGNOSTIC FEATURES OF THE XRT73LC00A ............................................................................. 43
4.1 THE ANALOG LOCAL LOOP-BACK MODE ................................................................................................. 43
FIGURE 29. THE ANALOG LOCAL LOOP-BACK IN THE XRT73LC00A ............................................................................................... 44
COMMAND REGISTER CR4 (ADDRESS = 0X04)............................................................................................. 44
4.2 THE DIGITAL LOCAL LOOP-BACK MODE .................................................................................................. 44
FIGURE 30. THE DIGITAL LOCAL LOOP-BACK PATH IN THE XRT73LC00A ....................................................................................... 45
COMMAND REGISTER CR4 (ADDRESS = 0X04)............................................................................................. 45
4.3 THE REMOTE LOOP-BACK MODE .............................................................................................................. 45
FIGURE 31. THE REMOTE LOOP-BACK PATH IN THE XRT73LC00A................................................................................................. 46
COMMAND REGISTER CR4 (ADDRESS = 0X04)............................................................................................. 46
4.4 TXOFF FEATURES ........................................................................................................................................ 46
COMMAND REGISTER CR1 (ADDRESS = 0X01)............................................................................................. 47
4.5 THE TRANSMIT DRIVE MONITOR FEATURES ........................................................................................... 47
FIGURE 32. THE XRT73LC00A EMPLOYING THE TRANSMIT DRIVE MONITOR FEATURES ................................................................. 47
FIGURE 33. TWO LIU’S, EACH MONITORING THE TRANSMIT OUTPUT SIGNAL OF THE OTHER LIU IC ............................................... 48
4.6 THE TAOS (TRANSMIT ALL ONES) FEATURE ........................................................................................... 48
COMMAND REGISTER CR1 (ADDRESS = 0X01)............................................................................................. 49
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