
á
XRT73L04
4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
PRELIMINARY
REV. P1.0.5
27
TxClk(n) is the clock signal that is of the selected data
rate frequency, E3 = 34.368 MHz, DS3 = 44.736 MHz
and STS-1 = 51.84 MHz. If the Transmit Section
samples a "1" on the TPData(n) input pin, then the
Transmit Section of the device ultimately generates a
positive polarity pulse via the TTIP(n) and TRing(n)
output pins across a 1:1 transformer. Conversely, if
the Transmit Section samples a "1" on the TNData(n)
input pin, then the Transmit Section of the device ulti-
mately generates a negative polarity pulse via the
TTIP(n) and TRing(n) output pins across a 1:1 trans-
former.
2.1.2
Accepting Single-Rail Data from the Ter-
minal Equipment
To transmit data in a Single-Rail data from the Termi-
nal Equipment, configure the XRT73L04 in the HOST
Mode.
To Configure Channel(n) to accept Single-Rail Da-
ta from the Terminal Equipment:
Write a "1" into the (SR/DR)_(n) bit-field, within Com-
mand Register CR3-(n) shown below. (Please refer
toTable 2 for the Address of the individual (n) channel.
The Transmit Section (of each channel) samples this
input pin on the falling edge of the TxClk(n) clock sig-
nal and encodes this data into the appropriate bipolar
line signal across the TTIP(n) and TRing(n) output
pins.
N
OTES
:
1. In this mode, the Transmit Logic Block ignores the
TNData(n) input pin.
2. If the Transmit Section of a given channel is config-
ured to accept Single-Rail data from the Terminal
Equipment, the B3ZS/HDB3 Encoder must be
enabled.
Figure 13 Illustrates the behavior of the TPData(n)
and TxClk(n) signals when the Transmit Logic Block
has been configured to accept Single-Rail data from
the Terminal Equipment.
2.2
T
HE
T
RANSMIT
C
LOCK
D
UTY
C
YCLE
A
DJUST
C
IR
-
CUITRY
The on-chip Pulse-Shaping circuitry within the Trans-
mit Section of each Channel in the XRT73L04 gener-
F
IGURE
12. T
HE
XRT73L04 S
AMPLES
THE
DATA
ON
THE
TPD
ATA
AND
TND
ATA
INPUT
PINS
TxClk
TPData
TNData
Data 1 1 0
COMMAND REGISTER CR3-(N)
D4
D3
D2
D1
D0
(SR/
DR)_(n)
LOSMUT(n) RxOFF RxClk(n)INV Reserved
1
x
x
x
x
F
IGURE
13. T
HE
B
EHAVIOR
OF
THE
TPD
ATA
AND
T
X
C
LK
I
NPUT
S
GNALS
,
WHILE
THE
T
RANSMIT
L
OGIC
B
LOCK
IS
A
CCEPTING
S
INGLE
-R
AIL
D
ATA
FROM
THE
T
ERMINAL
E
QUIPMENT
TxClk
TPData
Data 1 1 0