XRT75R12D_06 Datasheet, PDF (3/134 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET

XRT75R12D
REV. 1.0.1 TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
TABLE OF CONTENTS
GENERAL DESCRIPTION.............................................................................................................. 1
APPLICATIONS ............................................................................................................................................................... 1
FIGURE 1. BLOCK DIAGRAM OF THE XRT 75R12D.................................................................................................................................. 1
ORDERING INFORMATION .................................................................................................................... 1
FEATURES..................................................................................................................................................................... 2
TRANSMIT INTERFACE CHARACTERISTICS ....................................................................................................................... 2
RECEIVE INTERFACE CHARACTERISTICS ......................................................................................................................... 2
PIN DESCRIPTIONS (BY FUNCTION) ........................................................................................... 3
SYSTEM-SIDE TRANSMIT INPUT AND TRANSMIT CONTROL PINS....................................................................................... 3
SYSTEM-SIDE RECEIVE OUTPUT AND RECEIVE CONTROL PINS ....................................................................................... 6
RECEIVE LINE SIDE PINS ............................................................................................................................................... 8
CLOCK INTERFACE......................................................................................................................................................... 9
GENERAL CONTROL PINS ............................................................................................................................................ 10
POWER SUPPLY PINS .................................................................................................................................................. 12
GROUND PINS ............................................................................................................................................................. 13
TABLE 1: LIST BY PIN NUMBER ............................................................................................................................................................. 14
FUNCTIONAL DESCRIPTION ...................................................................................................... 18
1.0 R3 TECHNOLOGY (RECONFIGURABLE, RELAYLESS REDUNDANCY) ....................................... 18
1.1 NETWORK ARCHITECTURE ......................................................................................................................... 18
FIGURE 2. NETWORK REDUNDANCY ARCHITECTURE .............................................................................................................................. 18
2.0 CLOCK SYNTHESIZER ....................................................................................................................... 19
FIGURE 3. SIMPLIFIED BLOCK DIAGRAM OF THE INPUT CLOCK CIRCUITRY DRIVING THE MICROPROCESSOR ............................................ 19
TABLE 2: REFERENCE CLOCK PERFORMANCE SPECIFICATIONS.............................................................................................................. 19
2.1 CLOCK DISTRIBUTION ................................................................................................................................. 20
FIGURE 4. CLOCK DISTRIBUTION CONGIFURED IN E3 MODE WITHOUT USING SFM ................................................................................ 20
3.0 THE RECEIVER SECTION .................................................................................................................. 21
FIGURE 5. RECEIVE PATH BLOCK DIAGRAM .......................................................................................................................................... 21
3.1 RECEIVE LINE INTERFACE .......................................................................................................................... 21
FIGURE 6. RECEIVE LINE INTERFACECONNECTION................................................................................................................................. 21
3.2 ADAPTIVE GAIN CONTROL (AGC) .............................................................................................................. 21
3.3 RECEIVE EQUALIZER ................................................................................................................................... 22
FIGURE 7. ACG/EQUALIZER BLOCK DIAGRAM ....................................................................................................................................... 22
3.3.1 RECOMMENDATIONS FOR EQUALIZER SETTINGS .............................................................................................. 22
3.4 CLOCK AND DATA RECOVERY ................................................................................................................... 22
3.4.1 DATA/CLOCK RECOVERY MODE ............................................................................................................................ 22
3.4.2 TRAINING MODE........................................................................................................................................................ 22
3.5 LOS (LOSS OF SIGNAL) DETECTOR ........................................................................................................... 23
3.5.1 DS3/STS-1 LOS CONDITION ..................................................................................................................................... 23
TABLE 3: THE ALOS (ANALOG LOS) DECLARATION AND CLEARANCE THRESHOLDS FOR A GIVEN SETTING OF REQEN (DS3 AND STS-1 AP-
PLICATIONS).......................................................................................................................................................................... 23
3.5.2 DISABLING ALOS/DLOS DETECTION ..................................................................................................................... 23
3.5.3 E3 LOS CONDITION:.................................................................................................................................................. 23
FIGURE 8. LOSS OF SIGNAL DEFINITION FOR E3 AS PER ITU-T G.775 .................................................................................................. 23
FIGURE 9. LOSS OF SIGNAL DEFINITION FOR E3 AS PER ITU-T G.775................................................................................................... 24
3.5.4 INTERFERENCE TOLERANCE.................................................................................................................................. 24
FIGURE 10. INTERFERENCE MARGIN TEST SET UP FOR DS3/STS-1 ...................................................................................................... 24
FIGURE 11. INTERFERENCE MARGIN TEST SET UP FOR E3. ................................................................................................................... 24
TABLE 4: INTERFERENCE MARGIN TEST RESULTS ................................................................................................................................. 25
3.5.5 MUTING THE RECOVERED DATA WITH LOS CONDITION:................................................................................... 26
FIGURE 12. RECEIVER DATA OUTPUT AND CODE VIOLATION TIMING ........................................................................................................ 26
3.6 B3ZS/HDB3 DECODER .................................................................................................................................. 26
4.0 THE TRANSMITTER SECTION ........................................................................................................... 27
FIGURE 13. TRANSMIT PATH BLOCK DIAGRAM ...................................................................................................................................... 27
FIGURE 14. TYPICAL INTERFACE BETWEEN TERMINAL EQUIPMENT AND THE XRT75R12D (DUAL-RAIL DATA)............................................ 27
FIGURE 15. TRANSMITTER TERMINAL INPUT TIMING............................................................................................................................... 28
FIGURE 16. SINGLE-RAIL OR NRZ DATA FORMAT (ENCODER AND DECODER ARE ENABLED) .................................................................. 28
4.1 TRANSMIT CLOCK ........................................................................................................................................ 29
4.2 B3ZS/HDB3 ENCODER .................................................................................................................................. 29
4.2.1 B3ZS ENCODING ....................................................................................................................................................... 29
FIGURE 18. B3ZS ENCODING FORMAT ................................................................................................................................................. 29
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