XRT72L13 Datasheet, PDF (70/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13 MULTIPLEXER/FRAMER IC
REV. 1.0.6
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PRELIMINARY
FIGURE 28. ILLUSTRATION OF THE XRT72L13 OPERATING IN THE "DS2/ITU-T G.747 TRIBUTARY LOOP-BACK
MODE
TxPOS
TxNEG
TxLineClk
RxPOS
RxNEG
RxLineClk
CCleleaarrCChhaannnneel _l
DDSS33FFrraammeerr
32/64 Bit
De-Jitter
FIFO
DS2/G.747 Loop-Back Path
(Data and Clock are both Looped
Back)
M23
MUX
M23
DEMUX
MMicicrroopprroocceessssoorr
IInnteterrfafaccee
M12
MUX
TxDS1[0: 27]
TxClk[0:27]
M12
DEMUX
RxDS1[0: 27]
RxClk[0:27]
As Figure 28 indicates, a given DS2 or ITU-T G.747
line can be commanded into the "DS2/ITU-T G.747
Tributary Loop-Back" Mode. When this happens,
then a selected DS2 or ITU-T G.747 data stream (in
the Receive Path) is looped back into the Transmit
Path. It is important to note that the corresponding
DS2 or ITU-T G.747 clock signal is also looped back
into the Transmit Path.
1.2 XRT72L13 OPERATION WHILE IN THE
"CLEAR CHANNEL DS3 FRAMER MODE"
Figure 29 presents a functional block diagram of the
XRT72L13 when it has been configured to operate in
the "Clear Channel DS3 Framer Mode".
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