XRT73L03A Datasheet, PDF (49/62 Pages) Exar Corporation – 3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT

XRT73L03A
3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 2.0.4
FIGURE 33. THE BEHAVIOR OF THE RPOS AND RXCLK OUTPUT SIGNALS WHILE THE XRT73L03A IS TRANSMIT-
TING SINGLE-RAIL DATA TO THE RECEIVING TERMINAL EQUIPMENT
RPOS
RxClk
NOTE: The RNEG_(n) output pin is internally tied to Ground
whenever this feature is implemented.
3.7 SHUTTING OFF THE RECEIVE SECTION
The Receive Section of each channel in the
XRT73L03A can be shut off. This feature may come
in handy in some redundant system designs. Particu-
larly, in those designs where the Receive Termination
within the Secondary LIU Line Card has been
switched-out and is not receiving any traffic in parallel
with the Primary Line Card. In this case, having the
LIU on the Secondary Line Card consume the normal
amount of current is a waste of power. This feature
can permit powering down the Receive Section of the
LIU’s on the Secondary Line Card which reduces
their power consumption by approximately 80%
a. Operating in the Hardware Mode
Shut off the Receive Sections by pulling the RxOFF
input pin “High". Turn on the Receiver Sections by
pulling the RxOFF input pin to “Low".
b. Operating in the HOST Mode
Shut off the Receive Sections by writing a "1" into the
RxOFF bit-field within Command Register CR3-(n).
COMMAND REGISTER CR3-(n)
D4
D3
D2
D1
D0
(SR/ LOSMUT_(n) RxOFF_(n) RxClk_(n)INV Reserved
DR)_(n)
X
X
1
X
X
Turn on the Receive Section of Channel(n) by writing
a "0" into the RxOFF bit-field within Command Regis-
ter CR3-(n).
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