XRT72L53 Datasheet, PDF (13/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L53
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.7
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PRELIMINARY
PIN DESCRIPTION CONNECTED PINS
PIN #
C14
PIN NAME
TxOHIns[0]/
TYPE
I
DESCRIPTION
Transmit Overhead Data Insert Input/Transmit HDLC Data Input -
Bit 4; Channel 0:
The exact functionality of this input pin depends upon whether Channel
0 has been configured to operate in the “High-Speed HDLC Controller”
Mode or not.
TxHDLCDat4[0]
C15
TxNib1[1]/
TxHDLCDat1[1]
C16
TxSer[1]/
SndMsg[1]
C17
TxFrame[1]
C18
RxNib1[1]/
RxHDLCDat[1]
C19
RxNib3[1]/
RxHDLCDat3[1]
Non-High Speed HDLC Controller Mode:
Asserting this input signal (e.g., setting it "High") enables the Transmit
Overhead Data Input Interface (of Channel 0) to accept overhead data
from the Terminal Equipment. In other words, while this input pin is
"High", the Transmit Overhead Data Input Interface will sample the data
at the TxOH[0] input pin, on the falling edge of the TxOHClk[0] output
signal.
Conversely, setting this pin "Low" configures the Transmit Overhead
Data Input Interface to NOT sample (e.g., ignore) the data at the
TxOH[0] input pin, on the falling edge of the TxOHClk[0] output signal.
NOTE: If the Terminal Equipment attempts to insert an overhead bit that
cannot be accepted by the Transmit Overhead Data Input Interface
(e.g., if the Terminal Equipment asserts the TxOHIns signal, at a time
when one of these non-insertable overhead bits are being processed);
that particular insertion effort will be ignored.
High-Speed HDLC Controller Mode - Transmit HDLC Data Input -
Bit 4; Channel 0:
This pin functions as bit 4, within the byte-wide Transmit HDLC Control-
ler input interface (TxHDLCDat[7:0]), whenever Channel 0 has been
configured to operate in the “High-Speed HDLC Controller Mode.
I
Transmit Nibble-Parallel Payload Data Input - Bit 1/Transmit HDLC
Data Input - Bit 1; Channel 1:
See Description for Pin E17
I
Transmit Serial Payload Data Input/Transmit HDLC Controller -
SEND MESSAGE input - Channel 1:
See Description for Pin E18
O
Transmit End of DS3 or E3 Frame Indicator - Channel 1:
See Description for Pin E20
O
Receive Nibble Output - Bit 1/Receive HDLC Data Output - Bit 1;
Channel 1:
See Description for Pin G20
O
Receive Nibble Output - Bit 3/Receive HDLC Data Output - Bit 3;
Channel 1:
See Description for Pin H19
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