XRT73LC04A
4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 1.0.1
OPERATING MODE SELECT
P
IN
#
69
N
AME
SR/DR/CS
T
YPE
I
D
ESCRIPTION
Microprocessor Serial Interface - Chip Select Input/Encoder-
Decoder Disable Input:
The function of this pin depends upon whether the XRT73LC04A is oper-
ating in the HOST Mode or in the Hardware Mode.
N
OTE
:
This pin is internally pulled "High".
Hardware Mode - Receive Output Single-Rail/Dual-Rail Select:
In Hardware Mode, setting this pin “High” configures each of the four
channels to operate in the Single-Rail Mode. When each of the four
channels are configured to operate in the Single-Rail Mode, then the
Receive Section of each channel will output data via the RPOS_(n) out-
put pin.
N
OTE
:
Tie the TNData_(n) input to GND to enable HDB3/B3ZS Encod-
ing and Decoding.
Setting this pin “Low” configures each of the four channels to operate in
the Dual-Rail Mode. When each of the four channels are configured to
operate in the Dual-Rail Mode, then the Receive Section of each chan-
nel will output data via both the RPOS_(n) and RNEG_(n) output pins.
N
OTE
:
This input pin functions as the CS input pin, if the XRT73LC04A
device has been configured to operate in the HOST Mode.
72
71
E3_0/SDO
E3_1/SDI
I/O
I
E3_Mode Select - Channel 0:
This pin has a dual function. In HOST mode, this pin functions as SDO.
E3_Mode Select - Channel 1
This pin has a dual function. In HOST mode,this pin functions as SDI.
E3_Mode Select - Channel 2
E3_Mode Select - Channel 3
Hardware Mode Operation - E3 Mode Select - Channel (n):
This input pin is used to configure Channel (n) of the XRT73LC04A to
operate in the E3 or STS-1/DS3 Modes. Setting this input pin to "High"
configures Channel (n) to operate in the E3 Mode. Setting it "Low" con-
figures Channel (n) to operate in either the DS3 or STS-1 Modes,
depending upon the state of the STS-1/DS3_(n) input pin.
N
OTE
:
This pin is internally pulled “Low” when XRT73LC04A is in the
Hardware Mode.
STS-1/DS3 Select Input - Channel (n):
“High” for STS-1 and “Low” for DS3 Operation.
The XRT73LC04A ignores this pin if the E3_(n) pin is set to "1".
This input pin is ignored if the XRT73LC04A is operating in the HOST
Mode.
N
OTE
:
This pin should be tied to GND if the XRT73LC04A is going to be
operating in the HOST Mode, (internally pulled-down).
108
107
E3_2
E3_3
I
I
73
83
106
98
STS1/DS3_0
STS1/DS3_1
STS1/DS3_2
STS1/DS3_3
I
8
EXAR [ EXAR CORPORATION ]
