xrt83l30 Exar Corporation, xrt83l30 Datasheet - Page 18

• Manufacturer Part Number: xrt83l30
• Description: Xrt83l30 -single-channel T1/e1/j1 Long-haul, Short-haul Line Interface Unit
• Manufacturer: Exar Corporation

ALARM FUNCTION/OTHER
XRT83L30
SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
S
IGNAL
NLCDE1
NLCDE0
INSBPV
N
AME
P
33
34
35
IN
#
T
YPE
I
I
Network Loop Code Detection Enable pin 1
Network Loop Code Detection Enable pin 0
NLCDE[1:0] pins are used to control the Loop-Code detection according to
the following table:
When NLCDE1=”0” and NCLDE0=”1”, or NLCDE1=”1” and NLCDE0=”0”, the
chip is manually programed to monitor the receive data for the Loop-Up or
Loop-Down code respectively. When the presence of the “00001” or “001”
pattern is detected for more than 5 seconds, the NLCD pin is set to “1” and
the host has the option to activate the loop-back function manually.
Setting the NLCDE1=”1” and NLCDE0=”1” enables the Automatic Loop-
Code detection and Remote-Loop-Back activation mode. As this mode is ini-
tiated, the state of the NLCD pin is reset to “0” and the chip is programmed to
monitor the receive data for the Loop-Up Code. If the “00001” pattern is
detected for longer than 5 seconds, the NLCD pin is set to “1”, Remote Loop-
Back is activated and the chip is automatically programed to monitor the
receive data for the Loop-Down code. The NLCD pin stays “High” even after
the chip stops receiving the Loop-Up code. The remote Loop-Back condition
is removed when the chip receives the Loop-Down code for more than 5 sec-
onds or if the Automatic Loop-Code detection mode is terminated.
Insert Bipolar Violation
When this pin transitions from "0" to "1", a bipolar violation is inserted in the
transmitted data stream. Bipolar violation can be inserted either in the QRSS
pattern, or input data when operating in single-rail mode. The state of this pin
is sampled on the rising edge of TCLK.
N
OTE
: To ensure the insertion of a bipolar violation, this pin should be reset
to a "0" prior to setting to a "1".
NLCDE1
15
0
0
1
1
NLCDE0
0
1
0
1
D
ESCRIPTION
Detect Loop-Down Code in
Detect Loop-Up Code in
Automatic Loop-Code
Disable Loop-Code
Receive Data
Receive Data
Function
Detection
Detection
REV. 1.0.1