XRT72L53 Datasheet, PDF (22/467 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 #
F20
PIN NAME
RxFrame[0]
G1
TxInClk[1]
G2
RxNEG[1]
G3
TxFrameRef[1]
G4
TxInClk[0]
TYPE
O
I
I
I
I
DESCRIPTION
Receive Boundary of DS3 or E3 Frame Output Indicator - Channel
0:
The exact functionality of this output pin depends upon whether Chan-
nel 0 is operating in the “Serial” or “Nibble-Parallel” Mode.
Serial Mode Operation:
The Receive Section of Channel 0 will pulse this output pin “high” (for
one bit-period) when the “Receive Payload Data Output Interface” block
is driving the very first bit of a given DS3 or E3 frame, onto the
“RxSer[0]” output pin.
Nibble-Parallel Operation:
The Receive Section of Channel 0 will pulse this output pin “high” (for
one nibble-period), when the “Receive Payload Data Output Interface”
block is driving the very first nibble of a given DS3 or E3 frame, onto the
“RxNib[3:0][0] output pins.
Transmit Framer Reference Clock Input - Channel 1:
See Description for Pin G4
Receive Negative Data Input - Channel 1:
See Description for Pin F3
Transmit Framer Reference Input - Channel 1:
See Description for Pin E1
Transmit Framer Reference Clock Input - Channel 0:
This input pin functions as the Timing Reference for the Transmit Sec-
tion of Channel 0, within the XRT72L53 Framer IC; if the device has
been configured to operate in the Local-Time Mode. Further, if Channel
0 has been configured to operate in the Local-Time Mode, the Transmit
Payload Data Input Interface will sample the data at the TxSer[0] input
pin, upon the rising edge of TxInClk[0].
For E3 applications, the user should apply a 34.368MHz clock signal to
this input. Likewise, for DS3 applications, the user should apply a
44.736MHz clock signal to this input pin.
Channel 0, within the XRT72L53 Framer IC can be configured to oper-
ate in the Local-Time mode by writing "xxxx xx01" or "xxxx xx1x" into
the Framer Operating Mode register (Address = 0x00)
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