XRT73L04A
4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 2.0.3
47
N
OTE
: The RNEG_(n) output pin is internally tied to Ground
whenever this feature is implemented.
3.7
S
HUTTING
OFF
THE
R
ECEIVE
S
ECTION
The Receive Section of each channel in the
XRT73L04A 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).
Turn on the Receive Section of Channel(n) by writing
a "0" into the RxOFF bit-field within Command Regis-
ter CR3-(n).
F
IGURE
33. T
HE
BEHAVIOR
OF
THE
RPOS
AND
R
X
C
LK
OUTPUT
SIGNALS
WHILE
THE
XRT73L04A
IS
TRANSMIT
-
TING
S
INGLE
-R
AIL
DATA
TO
THE
R
ECEIVING
T
ERMINAL
E
QUIPMENT
RxClk
RPOS
COMMAND REGISTER CR3-(n)
D4
D3
D2
D1
D0
(SR/DR)_(n) LOSMUT_(n) RxOFF RxClk_(n)INV Reserved
X
X
1
X
X