XRT86VL38
PRELIMINARY
xr
OCTAL T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.6
275
D7
NLCDE1_n
Network Loop Code Detection Enable Bit 1:
This READ/WRITE bit-field together with NLCDE0_n (bit D6
within this register) are used to control the Loop-Code detec-
tion on the receive path of each channel
Loop-Up Code Detection Enable:
When NLCDE1 =”0” and NLCDE0 = “1”, the XRT86VL38 is
configured to monitor the receive data for the Loop-Up code
Pattern (i.e. a string of four ‘0’s follow by one ‘1’ pattern).
When the presence of the “00001” pattern is detected for
more than 5 seconds, the status of the NLCD bit (bit 3 of regis-
ter 0x0Fn5) is set to “1” and if the NLCD interrupt is enabled
(bit 3 of register 0x0Fn4), an interrupt will be generated.
Loop-Down Code Detection Enable:
When NLCDE1 =”1” and NLCDE0 = “0”, the XRT86VL38 is
configured to monitor the receive data for the Loop-Down
code Pattern (i.e. a string of two ‘0’s follow by one ‘1’ pattern).
When the presence of the “001” pattern is detected for more
than 5 seconds, the status of the NLCD bit (bit 3 of register
0x0Fn5) is set to “1” and if the NLCD interrupt is enabled (bit 3
of register 0x0Fn4), an interrupt will be generated.
Automatic Loop-Up Code Detection and Remote Loop Back
Activation Enable:
Setting the NLCDE1 = “1” and NLCDE0 = “1” enables the
Automatic Loop-Code detection and Remote Loop-Back acti-
vation mode. When this mode is enabled, the state of the
NLCD bit (bit 3 of register 0x0Fn5) is reset to “0” and the
XRT86VL38 is configured to monitor the receive data for the
Loop-Up code. If the “00001” pattern is detected for longer
than 5 seconds, then the NLCD bit (bit 3 of register 0x0Fn5) is
set “1”, and Remote Loop-Back is activated. Once the remote
loop-back is activated, the XRT86VL38 is automatically pro-
grammed to monitor the receive data for the Loop-Down code.
The NLCD bit stays set even after the chip stops receiving the
Loop-Up code.
The Remote Loop-Back condition is removed only when the
XRT86VL38 receives the Loop-Down code for more than 5
seconds or if the Automatic Loop-Code detection mode is ter-
minated.
The following table presents the different loop-code detection
corresponds to the setting of the NLCDE[1:0] bits..
R/W
0
T
ABLE
159: M
ICROPROCESSOR
R
EGISTER
#558, 574, 590, 606, 622, 638, 654 & 670 B
IT
D
ESCRIPTION
NLCDE[1:0]
N
ETWORK
L
OOP
C
ODE
D
ETECTION
E
NABLE
00
Disables Loop Code Detection
01
Enables Loop-Up Code Detection on
the Receive Path.
10
Enables Loop-Down Code Detection
on the Receive Path.
11
Enables Automatic Loop-Up Code
Detection on the Receive Path and
Remote Loop-Back Activation upon
detecting Loop-Up Code.