XRT82D20ES Exar, XRT82D20ES Datasheet - Page 24

• Manufacturer Part Number: XRT82D20ES
• Description: Peripheral Drivers & Components - PCIs 1 CH E1 LIU
• Manufacturer: Exar

Specifications of XRT82D20ES

• Product Category: Peripheral Drivers & Components - PCIs
• Rohs: yes

XRT82D20
SINGLE CHANNEL E1 LINE INTERFACE UNIT
In order to support diagnostic operations, the XRT82D20 supports the following loop-back modes:
•
•
•
Each of these loop-back modes will be discussed below.
When the XRT82D20 is configured to operate in the Local Loop-Back Mode, the XRT82D20 will ignore any
signals that are input to the RTIP and RRing input pins. The Transmitting Terminal Equipment will transmit
data into the XRT82D20 via the TPOS, TNEG and TClk input pins. This data will be processed through the
Transmit Terminal Input Interface and the Pulse Shaping circuit. Finally, this data will be output to the line via
the TTIP and TRing output pins. Additionally, this data (which is being output via the TTIP and TRing output
pins) will be looped back into the Receiver block. As a consequence, this data will also be processed through
the entire Receive Section of the XRT82D20. After this post-loop-back data has been processed through the
Receive Section it will output, to the Near-End Receiving Terminal Equipment via the RPOS and RNEG output
pins.
Figure
operate in the Local Loop-Back Mode.
The user can configure the XRT82D20 to operate in the Local Loop-Back Mode, by pulling the LLoop input pin
(pin 9) to GND.
F
2.0 DIAGNOSTIC FEATURES
2.1
IGURE
Local Loopback
Remote Loopback
Digital Loopback
RNEG
TNEG
RPOS
TPOS
RClk
TClk
18, illustrates the path that the data takes (within the XRT82D20), when the chip is configured to
18. I
The Local Loop-Back Mode
LLUSTRATION OF THE
Decoder
Encoder
HDB3
HDB3
A
NALOG
MUX
MUX
L
OCAL
L
OOP
Jitter Attenuator
Generator
Recovery
23
Data &
Timing
Timing
-B
ACK WITHIN THE
Tx Pulse
Shaper
Detect
Slicer
LOS
Data
XRT82D20
Line
Driver
Detector
Loopback
Peak
Local
TTIP
TRing
RLOS
RTIP
RRing
MClk
REV. 1.0.8