Datasheet

____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
142 of 366
10.13.5.2 Local Loopback
In local loopback the AMI-, HDB3- or B8ZS-encoded transmit signal from the transmit formatter is looped back
toward the Rx framer. The data is transmitted normally on TTIP/TRING if the line drive
r is enabled, but the
recovered clock and data from the LIU receiver is ignored. This loopback is shown in Figure 10-76.
Figure 10-76. Local Loopback
Transmit
Framer
Receive
Framer
Optional
Jitter
Attenuator
Optional
Jitter
Attenuator
Line
Driver
Transmit
Digital
Transmit
Analog
Receive
Digital
Receive
Analog
RTIP
RRING
RCLK
RSER
TCLK
TSER
TTIP
TRING
10.13.5.3 Remote Loopback
In remote loopback the recovered clock and data from the LIU receiver are looped back to the LIU transmitter. The
recovered clock and data are passed to the Rx framer, but the data stream from the transmit formatter is ignored.
This loopback is shown in Figure 10-77.
Figure 10-77. Remote Loopback
Transmit
Framer
Receive
Framer
Optional
Jitter
Attenuator
Optional
Jitter
Attenuator
Line
Driver
Transmit
Digital
Transmit
Analog
Receive
Digital
Receive
Analog
RTIP
RRING
RCLK
RSER
TCLK
TSER
TTIP
TRING
10.13.5.4 Dual Loopback
Dual loopback is local loopback and remote loopback at the same time. This loopback is shown in Figure 10-78.