XRT73LC03A Datasheet, PDF (10/61 Pages) Exar Corporation – 3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT

XRT73LC03A
3 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 1.0.1
OPERATING MODE SELECT
PIN #
64
NAME
SDO/(E3_0)
92
E3_1
102
E3_2
65
STS-1/DS3_0
95
STS-1/DS3_1
101 STS-1/DS3_2
42
HOST/(HW)
TYPE
I/O
I
I
I
DESCRIPTION
Serial Data Output from the Microprocessor Serial Interface/
E3_Mode Select - Channel 0:
The function of this pin depends on whether the XRT73LC03A is operat-
ing in the HOST Mode or in the Hardware Mode.
HOST Mode Operation - Serial Data Output for the Microprocessor
Serial Interface:
This pin serially outputs the contents of the specified Command Register
during Read Operations. The data is updated on the falling edge of the
SClk input signal and tri-stated upon completion of data transfer.
Hardware Mode Operation - E3 Mode Select - Channel 0:
This input pin is used to configure Channel 0 in the XRT73LC03A to
operate in the E3 or STS/DS3 Modes. Setting this input pin to "High"
configures Channel 0 to operate in the E3 Mode. Setting this input pin to
"Low" configures Channel 0 to operate in either the DS3 or STS-1
Modes, depending upon the state of the STS-1/DS3_0 input pin.
NOTE: This pin is internally pulled “Low” when XRT73LC03A is in the
Hardware Mode.
E3 Select Input - Channel (n):
A "High" on this pin configures Channel (n) of the XRT73LC03A to oper-
ate in the E3 Mode.
A "Low" on this pin configures Channel (n) of the XRT73LC03A to check
the state of the STS-1/DS3_(n) input pin
NOTE: This input pin is ignored and should be connected to GND if the
XRT73LC03A is operating in the HOST Mode.
STS-1/DS3 Select Input - Channel (n):
“High” for STS-1 and “Low” for DS3 Operation.
The XRT73LC03A ignores this pin if the E3_(n) pin is set to "1".
This input pin is ignored if the XRT73LC03A is operating in the HOST
Mode.
NOTE: This pin should be tied to GND if the XRT73LC03A is going to be
operating in the HOST Mode, (internally pulled-down).
HOST/Hardware Mode Select:
This input pin is used to enable or disable the Microprocessor Serial
Interface (e.g., consisting of the SDI, SDO, SClk, and CS pins).
Setting this input pin "High" enables the Microprocessor Serial Interface
(e.g. configures the XRT73LC03A to operate in the HOST Mode). In this
mode, configure the XRT73LC03A via the Microprocessor Serial Inter-
face. When the XRT73LC03A is operating in the HOST Mode, then it
ignores the states of many of the discrete input pins.
Setting this input pin "Low" disables the Microprocessor Serial Interface
(e.g., configures the XRT73LC03A to operate in the Hardware Mode). In
this mode, many of the external input control pins are functional.
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