XRT73LC03A Datasheet, PDF (48/61 Pages) Exar Corporation – 3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT

XRT73LC03A
3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 1.0.1
FIGURE 32. THE BEHAVIOR OF THE RPOS AND RXCLK OUTPUT SIGNALS WHILE THE XRT73LC03A IS TRANS-
MITTING 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
XRT73LC03A can be shut off. This feature may
come in handy in some redundant system designs.
Particularly, in those designs where the Receive Ter-
mination 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, hav-
ing 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 Sec-
tion 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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