XRT72L54 Datasheet, PDF (30/484 Pages) Exar Corporation – FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L54
FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
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PRELIMINARY
PIN DESCRIPTION
PIN #
C15
C16
C17
C18
C19
C20
PIN NAME
TxNib1[1]/
TxHDLCDat1[1]
TxSer[1]/
SndMsg[1]
TxFrame[1]
RxNib1[1]/
RxHDLCDat[1]
RxNib3[1]/
RxHDLCDat3[1]
TxNib2[0]/
TxHDLCDat2[0]
D1
TxNEG[0]
D2
TRST
D3
TMS
D4
GND
D5
RxOOF[1]
D6
VDD
D7
TAOS[1]
D8
GND
TYPE
I
I
O
O
O
I
O
I
I
****
O
****
O
****
DESCRIPTION
See Description for Pin E17
See Description for Pin E18
See Description for Pin E20
See Description for Pin G20
See Description for Pin H19
Transmit Nibble-Parallel Payload Data Input -2:
The Terminal Equipment is expected to input data, that is intended to be
transmitted to the remote terminal, over an E3 or DS3 transport
medium. The Framer IC will take data, applied to this pin, and insert it
into an outbound "E3 or DS3" frame. The XRT72L54 device will sample
the data that is at these input pins, upon the rising edge of the "TxNib-
Clk" signal.
NOTE: This input pin is active only if the Nibble-Parallel Mode has been
selected.
Transmit HDLC Data Input - 2:
This pin accepts bit 2 TxHDLC data when the HDLC controller is turned
on.
Transmit Negative Polarity Pulse:
The exact role of this output pin depends upon whether the Framer is
operating in the Unipolar or Bipolar Mode.
Unipolar Mode:
This output signal pulses "high" for one bit period, at the end of each
"outbound" DS3 or E3 frame. This output signal is at a logic "low" for all
of the remaining bit-periods of the "outbound" DS3 or E3 frames
Bipolar Mode:
This output pin functions as one of the two dual-rail output signals that
commands the sequence of pulses to be driven on the line. TxPOS is
the other output pin. This input is typically connected to the TNDATA
input of the external DS3/E3 Line Interface Unit IC. When this output is
asserted, it will command the LIU to generate a negative polarity pulse
on the line.
JTAG Reset Pin: Resets Boundary Scan Logic.
Test Mode Select: Boundary Scan Mode Select input.
Ground
See Description for Pin A3
Power Supply +3.3v ± 5%
See Description for Pin C6
Ground
11