XRT73LC04A_08 Datasheet, PDF (6/64 Pages) Exar Corporation – 4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT

XRT73LC04A
4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 1.0.2
COMMAND REGISTER CR-2(N) ............................................................................................................ 37
3.3 CLOCK RECOVERY PLL .................................................................................................................. 38
The Training Mode ............................................................................................................................. 38
The Data/Clock Recovery Mode ........................................................................................................ 38
3.4 THE HDB3/B3ZS DECODER .......................................................................................................... 38
B3ZS Decoding (DS3/STS-1 Applications) ........................................................................................ 38
Figure 24.An Example of B3ZS Decoding ...................................................................................................... 38
HDB3 Decoding (E3 Applications) ..................................................................................................... 38
Figure 25.An Example of HDB3 Decoding ...................................................................................................... 39
Configuring the HDB3/B3ZS Decoder ................................................................................................ 39
COMMAND REGISTER CR3-(N) ............................................................................................................ 39
3.5 LOS DECLARATION/CLEARANCE ..................................................................................................... 39
The LOS Declaration/Clearance Criteria for E3 Applications ............................................................. 39
Figure 26.The Signal Levels that the XRT73LC04A declares and clears LOS ............................................... 40
Figure 27.The Behavior of the LOS Output Indicator in response to the Loss of Signal and the Restoration of
Signal ................................................................................................................................................ 41
The LOS Declaration/Clearance Criteria for DS3 and STS-1 Applications ........................................ 41
Table 5:The ALOS (Analog LOS) Declare and Clear Thresholds for a given setting of LOSTHR and REQEN
(DS3 and STS-1 Applications) ........................................................................................................... 41
COMMAND REGISTER CR0-(N) ............................................................................................................ 42
COMMAND REGISTER CR2-(N) ............................................................................................................ 42
COMMAND REGISTER CR0-(N) ............................................................................................................ 42
COMMAND REGISTER CR2-(N) ............................................................................................................ 42
Muting the Recovered Data while the LOS is being Declared ........................................................... 42
COMMAND REGISTER CR3-(N) ............................................................................................................ 43
3.6 ROUTING THE RECOVERED TIMING AND DATA INFORMATION TO THE RECEIVING TERMINAL EQUIPMENT .
43
Routing Dual-Rail Format Data to the Receiving Terminal Equipment .............................................. 43
Figure 28.The typical interface for the Transmission of Data in a Dual-Rail Format, from the Receive Section of
the XRT73LC04A to the Receiving Terminal Equipment .................................................................. 43
Figure 29.How the XRT73LC04A outputs data on the RPOS and RNEG output pins .................................... 44
Figure 30.The Behavior of the RPOS, RNEG, and RxClk signals when RxClk is inverted ............................. 44
COMMAND REGISTER CR3-(N) ............................................................................................................ 45
Routing Single-Rail Format (Binary Data Stream) data to the Receive Terminal Equipment ............ 45
COMMAND REGISTER CR3-(N) ............................................................................................................ 45
Figure 31.The typical interface for the Transmission of Data in a Single-Rail Format from the Receive Section
of the XRT73LC04A to the Receiving Terminal Equipment .............................................................. 45
Figure 32.The behavior of the RPOS and RxClk output signals while the XRT73LC04A is transmitting Single-
Rail data to the Receiving Terminal Equipment ................................................................................ 46
3.7 SHUTTING OFF THE RECEIVE SECTION ........................................................................................... 46
COMMAND REGISTER CR3-(N) ............................................................................................................ 46
4.0 DIAGNOSTIC FEATURES OF THE XRT73LC04A ................................................................................. 47
4.1 THE ANALOG LOCAL LOOP-BACK MODE ......................................................................................... 47
Figure 33. A channel operating in the Analog Local Loop-Back Mode ........................................................... 47
COMMAND REGISTER CR4-(N) ............................................................................................................ 48
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