XRT72L13 Datasheet, PDF (44/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
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PRELIMINARY
PIN DESCRIPTIONS
PIN #
181
NAME
RLOOP
182
LLOOP
183
DMO
TYPE
O
O
O
DESCRIPTION
Remote Loopback Output Pin (to the XRT7300 DS3/E3 Line Inter-
face Unit IC).
This output pin is intended to be connected to the RLOOP input pin of
the XRT7300 DS3/E3 Line Interface Unit IC. The user can command
this signal to toggle "high" and, in turn, force the XRT7300 DS3/E3
Line Interface Unit IC into the "Remote Loopback" mode. Conversely,
the user can command this signal to toggle "low" and allow the
XRT7300 to operate in the normal mode. (For a detailed description
of the XR-T7300 DS3/E3 Line Interface Unit IC's operation during
Remote Loopback, please see the XR-T7300 DS3/STS-1/ E3 Line
Interface Unit IC's Data Sheet).
Writing a "1" to bit 1 of the "Line Interface Drive Register (Address =
0x80) will cause this output pin to toggle "high". Writing a "0" to this
bit-field will cause the RLOOP output to toggle "low".
NOTE: This output pin can be used for a variety of other purposes if
the XRT7300 DS3/E3 LIU is not used.
Local Loopback Output Pin (to the XRT7300 DS3/E3 Line Inter-
face Unit IC).
This output pin is intended to be connected to the LLOOP input pin of
the XRT7300 LIU IC. The user can command this signal to toggle
"high" and, in turn, force the LIU into the "Local Loopback" mode.
(For a detailed description of the XRT7300 DS3/E3 Line Interface Unit
IC's operation during Local Loopback, please see the XRT7300 DS3/
STS-1/E3 Line Interface Unit IC's Data Sheet).
Writing a "1" to bit 1 of the "Line Interface Drive Register (Address =
0x80) will cause this output pin to toggle "high". Writing a "0" to this
bit-field will cause the RLOOP output to toggle "low".
NOTE: This output pin can be used for a variety of other purposes if
the XRT7300 DS3/E3 LIU is not used.
"Drive Monitor Output" Input (from the XRT7300 DS3 Line Inter-
face Unit IC).
This input pin is intended to be tied to the DMO output pin of the
XRT7300 DS3 Line Interface Unit IC. The user can determine the
state of this input pin by reading Bit 2 (DMO) within the Line Interface
Scan Register (Address = 0x81). If this input signal is "high", then it
means that the drive monitor circuitry (within the XRT7300 DS3 Line
Interface Unit IC) has not detected any bipolar signals at the MTIP
and MRING inputs within the last 128 ± 32 bit-periods. If this input
signal is "low", then it means that bipolar signals are being detected at
the MTIP and MRING input pins of the XRT7300.
NOTE: This output pin can be used for a variety of other purposes if
the XRT7300 DS3/E3 LIU is not used.
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