xrt75r12 Exar Corporation, xrt75r12 Datasheet - Page 46

• Manufacturer Part Number: xrt75r12
• Description: Twelve Channel E3/ds3/sts-1 Line Interface Unit With Jitter
• Manufacturer: Exar Corporation

XRT75R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
When the Digital Loopback is selected, the transmit clock TxClk_n and transmit data inputs (TxPOS_n &
TxNEG_n are looped back and output onto the RxClk_n, RxPOS_n and RxNEG_n pins as shown in
Figure
With Remote loopback activated as shown in
after the jitter attenuator (if selected in receive or transmit path) to the transmit path using RxClk as transmit
timing. The receive data is also output via the RxPOS and RxNEG pins.
N
F
F
6.2.2
6.2.3
OTE
IGURE
IGURE
: Input signals on TxClk, TxPOS and TxNEG are ignored during Remote loopback.
TxPOS
TxNEG
TxPOS
TxNEG
RxCLK
RxCLK
RxNEG
RxPOS
TxCLK
TxCLK
RxNEG
RxPOS
31.
31. D
32. R
DIGITAL LOOPBACK
REMOTE LOOPBACK
IGITAL
EMOTE
L
L
OOPBACK
OOPBACK
HDB3/B3ZS
DECODER
HDB3/B3ZS
HDB3/B3ZS
HDB3/B3ZS
DECODER
ENCODER
ENCODER
Figure
43
32, the receive data on RTIP and RRing is looped back
RECOVERY
RECOVERY
CONTROL
CONTROL
DATA &
DATA &
CLOCK
CLOCK
TIMING
TIMING
Tx
Rx
Tx
Rx
RTIP
TTIP
RRing
RTIP
TTIP
REV. 1.0.4
TRing
TRing
RRing