ds26518 Maxim Integrated Products, Inc., ds26518 Datasheet - Page 92

• Manufacturer Part Number: ds26518
• Description: 8-port T1/e1/j1 Transceiver
• Manufacturer: Maxim Integrated Products, Inc.

9.12.6 LIU Loopbacks
The DS26518 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 9-26. Loopback Diagram
9.12.6.1
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 9-27. Analog Loopback
RRING
TRING
MCLK
RTIP
TTIP
TCLK
TSER
RCLK
RSER
Analog Loopback
Transmit
Framer
Receive
Framer
Master Clock
RX LIU
TX LIU
PLL
Optional
Jitter
Attenuator
Optional
Jitter
Attenuator
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JACLK
Transmit
Digital
receive path
Attenuator
Attenuator
assigned to
Attenuator
or transmit
Receive
Digital
(in RX path)
(in TX path)
disabled
can be
path or
Jitter
Jitter
Jitter
Transmit
Analog
Receive
Analog
Figure
DS26518 8-Port T1/E1/J1 Transceiver
TX FORMATTER
9-27.
RX FRAMER
Line
Driver
TTIP
TRING
RTIP
RRING
TCLK
TSER
RCLK
RSER