
á
PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
33
If the user intends to interface the UNI to an optical
DS3 line, then the user can operate the UNI in the
“unipolar” mode. Additionally, the user would connect
the single-rail output pin of the UNI (TxPOS) to the
“Electrical” input of an “Electrical to Optical” converter;
and connect the single-rail input pin of the UNI
(RxPOS) to the “Electrical” output of an “Optical to
Electrical” converter. The “Electrical to Optical” and
“Optical to Electrical” converters are “entities” that
handle the translation between the electronic and
photonic modes. Figure 4 presents an illustration of the
“System Level” interfacing of the XRT7245 DS3 UNI,
when the DS3 line signal is transmitted over an
optical medium.
F
IGURE
3. S
YSTEM
L
EVEL
I
NTERFACING
OF
THE
XRT7245 DS3 UNI (DS3 D
ATA
IS
TRANSMITTED
OVER
C
OPPER
M
EDIUM
)
ATM
Layer
Processor
Line
Interface
Unit
Microprocessor
Interface
ALE_AS
XR-T7245
TxData
[15:0]
RxData
[15:0]
To/From
Far End
DS3 UNI
TxPOS
TxNEG
RxPOS
RxNEG
ATM Switch
Local “Housekeeping” Processor
D[15:0]
WRB_RW
RDS_DS
Rdy_Dtck
TxClav
RxClav
Transmit
Utopia
Interface
Block
Transmit
Cell
Processor
Transmit
PLCP
Processor
Transmit
DS3
Framer
Receive
Cell
Processor
Receive
Utopia
Interface
Block
Receive
PLCP
Processor
Receive
DS3
Framer
F
IGURE
4. S
YSTEM
L
EVEL
I
NTERFACING
OF
THE
XRT7245 DS3 UNI
(DS3
DATA
IS
TRANSMITTED
OVER
O
PTICAL
F
IBER
ATM
Layer
Processor
Electrical
to
Optical
Converter
Microprocessor
Interface
ALE_AS
XR-T7245
TxData
[15:0]
To/From
Far End
DS3 UNI
TxPOS
RxPOS
ATM Switch
Local “Housekeeping” Processor
D[15:0]
WRB_RW
RDS_DS
Rdy_Dtck
TxClav
RxClav
Transmit
Utopia
Interface
Block
Transmit
Cell
Processor
Transmit
PLCP
Processor
Transmit
DS3
Framer
Receive
Cell
Processor
Receive
Utopia
Interface
Block
Receive
PLCP
Processor
Receive
DS3
Framer
Optical
to
Electrical
Converter
RxData
[15:0]