XRT73L03 Datasheet, PDF (12/62 Pages) Exar Corporation – 3 CHANNEL E3/DS3/STS-1 LINE INTERFCE UNIT

XRT73L03 3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. P1.0.13
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PRELIMINARY
PIN DESCRIPTION
PIN #
61
62
63
SIGNAL NAME
CS/(ENDECDIS)
SClk/(RxOFF2)
SDI/(RxOFF1)
TYPE
I
I
I
DESCRIPTION
Microprocessor Serial Interface - Chip Select Input/Encoder-Decoder Dis-
able Input:
This pin’s functionality depends on whether the XRT73L03 is operating in the
HOST or Hardware Mode.
HOST Mode - Chip Select Input
The Local Microprocessor must assert this pin (set it to "0") in order to enable
communication with the XRT73L03 via the Microprocessor Serial Interface.
NOTE: This pin is internally pulled “High".
Hardware Mode - Encoder/Decoder Disable Input
Setting this input pin "High" disables the B3ZS/HDB3 Encoder & Decoder
blocks in the XRT73L03 and configures it to transmit and receive the line sig-
nal in an AMI format.
Setting this input pin "Low" enables the B3ZS/HDB3 Encoder & Decoder
blocks and configures it transmit and receive the line signal in the B3ZS format
for STS-1/DS3 operation or in the HDB3 format for E3 operation.
NOTE: If the XRT73L03 is operating in the Hardware Mode, this pin setting
configures the B3ZS/HDB3 Encoder and Decoder Blocks for all Channels.
Microprocessor Serial Interface Clock Signal/Channel 2 Receiver Shut
OFF Input:
The function of this pin depends on whether the XRT73L03 is operating in the
HOST Mode or in the Hardware Mode.
HOST Mode - Microprocessor Serial Interface Clock Signal:
This signal is used to sample the data on the SDI pin on the rising edge of this
signal. Additionally, during Read operations the Microprocessor Serial Inter-
face updates the SDO output on the falling edge of this signal.
Hardware Mode - Channel 2 Receiver Shut OFF input pin:
Setting this input pin "High" shuts off the Channel 2 receiver. Setting this input
pin "Low" enables the Receive Section for full operation.
Serial Data Input for the Microprocessor Serial Interface/Channel 1 -
Receiver Shut OFF Input pin:
The function of this input depends on whether the XRT73L03 is operating in
the HOST Mode or in the Hardware Mode.
HOST Mode - Serial Data Input for the Microprocessor Serial Interface:
To read or write data into the Command Registers over the Microprocessor
Serial Interface, apply the Read/Write bit, the Address Values of the Command
Registers and Data Value to be written during Write Operations to this pin.
This input is sampled on the rising edge of the SClk pin (pin 18).
Hardware Mode - Channel 1 Receiver Shut OFF Input pin:
Setting this input pin “High” shuts off the Channel 1 receiver. Setting this input
pin “Low” enables the Receive Section for full operation.
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