XRT72L53 Datasheet, PDF (20/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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PRELIMINARY
XRT72L53
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.7
PIN DESCRIPTION CONNECTED PINS
PIN #
F1
PIN NAME
RxLineClk[0]
F2
RxPOS[0]
F3
RxNEG[0]
F4
VDD
F17
VDD
TYPE
I
I
I
****
****
DESCRIPTION
Receiver LIU (Recovered) Clock Input - Channel 0:
This input signal serves three purposes:
1. The Receive Section of Channel 0 uses it to sample and latch the
signals at the RxPOS[0] and RxNEG[0] input pins (into the Receive
Framer circuitry).
2. This input signal functions as the timing reference for the Receive
Framer block, within Channel 0.
3. The Transmit Framer block (within Channel 0) can be configured to
use this input signal as its timing reference.
This signal is the recovered clock from the external DS3/E3 LIU (Line
Interface Unit) IC, which is derived from the incoming DS3/E3 data.
Receive Positive Data Input - Channel 0:
The exact role of this input pin depends upon whether Channel 0 is
operating in the Single-Rail or Dual-Rail Mode.
Single-Rail Mode:
This input pin functions as the Single-Rail input for the incoming E3 data
stream. The signal at this input pin will be sampled and latched (into the
Receive DS3/E3 Framer block within Channel 0) on the user-selected
edge of the RxLineClk[0] signal.
Dual-Rail Mode:
This input functions as one of the dual rail inputs for the incoming AMI/
HDB3/B3ZS encoded DS3 or E3 data that has been received from an
external Line Interface Unit (LIU) IC. RxNEG[0] functions as the other
dual rail input for the channel. When this input pin is asserted, it means
that the LIU has received a positive polarity pulse from the line.
Receive Negative Data Input - Channel 0:
The exact role of this input pin depends upon whether Channel 0 is
operating in the Single-Rail or Dual-Rail Mode.
Single-Rail Mode:
This input pin is inactive, and should be pulled “low” when Channel 0 is
operating in the Single-Rail Mode.
Dual-Rail Mode:
This input pin functions as one of the dual rail inputs for the incoming
AMI/HDB3/B3ZS encoded DS3 or E3 data that has been received from
an external Line Interface Unit (LIU) IC. RxPOS[0] functions as the
other dual rail input for the Channel. When this input pin is asserted, it
means that the LIU has received a negative polarity pulse from the line.
Power Supply +3.3v ± 5%
Power Supply +3.3v ± 5%
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