XRT7302IQ80 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT7302IQ80' PDF : 77 Pages View PDF
XRT7302 2 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
áç
REV. 1.1.0
Whenever the XRT7302 device accepts dual-rail data
from the Terminal Equipment, it does so via the fol-
lowing input signals.
• TPData
• TNData
• TxClk
Figure 7 presents an illustration of the typical inter-
face for the transmission of data in a "Dual-Rail" For-
mat between the Terminal Equipment and the Trans-
mit Section of the XRT7302 device.
FIGURE 7. ILLUSTRATION OF THE TYPICAL INTERFACE FOR THE TRANSMISSION OF DATA IN A DUAL RAIL FOR-
MAT, FROM THE "TRANSMITTING" TERMINAL EQUIPMENT TO THE "TRANSMIT SECTION" OF A CHANNEL WITHIN
THE XRT7302 DEVICE
Terminal
Equipment
(E3/DS3 or STS-1
Framer)
TxPOS
TxNEG
TxLineClk
TPData
TNData
TxClk
Transmit
Logic
Block
XRT7302 E3/DS3/STS-1 LIU
The manner that the LIU handles "Dual-Rail" data is
described below and is illustrated in Figure 8. The
Transmit Section (of a Channel) will typically sample
the data on the TPData and TNData input pins on the
falling edge of TxClk.
FIGURE 8. ILLUSTRATION ON HOW THE XRT7302 DEVICE SAMPLES THE DATA ON THE TPDATA AND TNDATA
INPUT PINS
Data
TPData
TNData
TxClk
1
1
0
TxClk is typically a clock signal that is of the selected
data rate frequency. For the E3 data rate, TxClk is
34.368 MHz. For the DS3 data rate, TxClk is 44.736
MHz, and for the SONET STS-1 rate, TxClk is 51.84
MHz. If the Transmit Section samples a "1" on the
TPData input pin, then the "Transmit Section" of the
device will ultimately generate a positive polarity
pulse via the TTIP and TRing output pins (across a
1:1 transformer). Conversely, if the Transmit Section
samples a "1" on the TNData input pin, then the
"Transmit Section" of the device will ultimately gener-
ate a negative polarity pulse via the TTIP and TRing
output pins (across a 1:1 transformer).
2.1.2 Accepting "Single-Rail" Data from the
Terminal Equipment
30
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