XRT73R12_07 Datasheet, PDF (47/89 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

XRT73R12
REV. 1.0.2
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
6.3 TRANSMIT ALL ONES (TAOS)
Transmit All Ones (TAOS) can be set by setting the TAOS_n control bits to “1” in the Channel control registers.
When the TAOS is set, the Transmit Section generates and transmits a continuous AMI all “1’s” pattern on
TTIP_n and TRing_n pins. The frequency of this ones pattern is determined by TxClk_n. the TAOS data path
is shown in Figure 33. TAOS does not operate in Analog loopback or Remote loopback modes, however will
function in Digital loopback mode.
FIGURE 33. TRANSMIT ALL ONES (TAOS)
TxCLK
TxPOS
TxNEG
HDB3/B3ZS
ENCODER
TIMING
CONTROL
TAOS
TTIP
Tx
Transmit All 1's
TRing
RxCLK
RxPOS
RxNEG
HDB3/B3ZS
DECODER
DATA &
CLOCK
RECOVERY
RTIP
Rx
RRing
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