XRT7250 Datasheet, PDF (33/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

XRT7250 DS3/E3 FRAMER IC
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REV. 1.1.1
PIN DESCRIPTION
PIN #
78
NAME
ExtLOS
79
DMO
80
VDD
81
GND
82
RxNib3
83
RxNib2
84
RxNib1
TYPE
DESCRIPTION
I Receive LOS (Loss of Signal) Indicator Input (from XRT7300 LIU
IC).
This input pin is intended to be connected to the RLOS (Receive Loss of Sig-
nal) output pin of the XRT7300 Line Interface Unit IC. The user can monitor the
state of this pin by reading the state of Bit 0 (RLOS) within the Line Interface
Scan Register (Address = 0x81).
If this input pin is "low", then it means that the XRT7300 device is currently
NOT declaring an "LOS (Loss of Signal) condition. However, if this input pin is
"high", then it means that the XRT7300 device is currently declaring an LOS
(Loss of Signal) condition.
For more information on the operation of the XR-T7300 DS3/E3 Line Receiver
IC, please consult the "XRT7300 DS3/STS-1/E3 Line Interface Unit IC" data
sheet.
Asserting the RLOS input pin will cause the XRT7250 DS3/E3 Framer device
to declare an "LOS (Loss of Signal) condition. Therefore, this input pin should
not be used as a general purpose input.
I "Drive Monitor Output" Input (from the XR-T7300 DS3/E3 Line
Interface Unit IC).
This input pin is intended to be tied to the DMO output pin of the XRT7300
DS3/E3 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/E3 Line Interface Unit IC) has not detected any bipo-
lar 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 device.
If this customer is not using the XR-T7300 DS3/E3 Line Interface Unit IC, then
he/she can use this input pin for a variety of other purposes.
**** Power Supply Pin
**** Ground Pin
O Receive Nibble Output - 3
The Framer IC will output "Received data (from the Remote Terminal) to the
local Terminal Equipment via this pin along with RxNib0, RxNib1 and RxNib2.
The data at this pin is updated on the rising edge of the RxClk output signal.
NOTE: This output pin is active only if the Nibble-Parallel Mode has been
selected.
O Receive Nibble Output - 2
The Framer IC will output "Received data (from the Remote Terminal) to the
local Terminal Equipment via this pin along with RxNib0, RxNib1 and RxNib2.
The data at this pin is updated on the rising edge of the RxClk output signal.
NOTE: This output pin is active only if the Nibble-Parallel Mode has been
selected.
Receive Nibble Output - 1
The Framer IC will output "Received data (from the Remote Terminal) to the
local Terminal Equipment via this pin along with RxNib0, RxNib2 and RxNib3.
The data at this pin is updated on the rising edge of the RxClk output signal.
NOTE: This output pin is active only if the Nibble-Parallel Mode has been
selected.
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