Rainbow Electronics DS26519 - Manual (Page 103)

DS26519 16-Port T1/E1/J1 Transceiver
103 of 310
9.12.6 LIU Loopbacks
The DS26519 provides four LIU loopbacks for diagnostic purposes: Analog Loopback, Local Loopback, Remote
Loopback 1, and Remote Loopback 2. Dual Loopback is a combination of Local Loopback and Remote Loopback
1. In the loopback diagrams that follow, TSERn, TCLKn, RSERn, and RCLKn are inputs/outputs from the framer.
Figure 9-27. Loopback Diagram
Jitter
Attenuator
(in RX path)
RSER
Jitter
Attenuator
(in TX path)
Local
Loopback
Jitter
Attenuator
can be
assigned to
receive path
or transmit
path or
disabled
RTIP
RRING
TTIP
TRING
JACLK
Master Clock
PLL MCLK
RCLK
Anal
og Loopback
Remot
e 2 Loopback
Remot
e 1 Loopback
TSER
TCLK
RX LIU
TX LIU TX FORMATTER
RX FRAMER
9.12.6.1 Analog Loopback
The analog output of the transmitter TTIPn and TRINGn is looped back to RTIPn and RRINGn of the receiver. Data
at RTIPn and RRINGn is ignored in analog loopback. This is shown in the
Figure 9-28 .
Figure 9-28. Analog Loopback
Line
Driver
Transmit
Framer
Optional
Jitter
Attenuator
Transmit
Digital Transmit
Analog
TCLK
Receive
Framer
Optional
Jitter
Attenuator
Receive
Digital Receive
Analog
RCLK RTIP
RRING
TSER
RSER
TTIP
TRING