XRT72L53 Datasheet, PDF (7/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L53
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.7
áç
PRELIMINARY
PIN DESCRIPTION CONNECTED PINS
PIN #
B6
B7
PIN NAME
Req[1]
RLOOP[0]
B8
RLOL[0]
B9
DMO[1]
B10
RxOH[1]/
RxHDLCDat6[1]
B11
TxOHIns[1]/
TxHDLCDat4[1]
B12
TxAISEn[1]
TYPE
O
O
I
I
O
I
I
DESCRIPTION
Receive Equalization Enable/Disable Select output pin - Channel 1:
See Description for Pin A5
Remote Loopback Output Pin - Channel 0 (to be connected to DS3/
E3 Line Interface Unit IC):
This output pin is intended to be connected to the RLOOP input pin of
the DS3/E3 Line Interface Unit IC. The user can command this signal to
toggle "High" and, in turn, force the DS3/E3 Line Interface Unit IC into
either the Remote or Digital Local- Loopback modes (depending upon
the state of the LLOOP[0] pin. Conversely, the user can command this
signal to toggle "Low" and allow the XRT7300 device to operate in the
normal mode.
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 as a General Purpose Output pin.
Receive Loss of Lock Indicator input pin - Channel 0 (from the
DS3/E3 Line Interface Unit IC):
This input pin is intended to be connected to the RLOL (Receive Loss of
Lock) output pin of the DS3/E3 Line Interface Unit IC. The user can
monitor the state of this pin by reading the state of Bit 1 (RLOL) within
the Line Interface Scan Register (Address = 0x81).
If this input pin is "Low", then it means that the clock recovery phase-
locked-loop circuitry, within the LIU device is properly locked onto the
incoming DS3 E3 data-stream; and is properly recovering clock and
data from this DS3/E3 data-stream. However, if this input pin is "High",
then it means that the phase-locked-loop circuitry, within the LIU device
has lost lock with the incoming DS3 or E3 data-stream, and is not prop-
erly recovering clock and data.
If the customer is not using an “Exar XRT73L0X Family of DS3/E3 LIU
ICs, then this input pin can be used for other purposes.
Drive Monitor Output input pin - Channel 1 (from the DS3/E3 LIU
IC):
See Description for Pin C9
Receive Overhead Data Output port/Receive HDLC Data Output -
Bit 6; Channel 1:
See Description for Pin C12
Transmit Overhead Data Insert Input/Transmit HDLC Data Input -
Bit 4 - Channel 1:
See Description for Pin C14
Transmit AIS Command Input - Channel 1:
See Description for Pin B15
7