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PRELIMINARY
XRT79L71
332
REV. P2.0.0
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
The purpose of the Transmit DS3/E3 LIU Block is to accept a DS3/E3 data-stream from the Transmit DS3/E3
Framer block and to perform all of the following operations on this data.
To convert this "outbound" data into the B3ZS line code (for DS3 applications) or into the HDB3 line code (for
E3 applications).
For DS3 Applications, to further convert this data into a DS3 line signal such that each pulse that is
generated by the Transmit DS3 LIU block will comply with the Isolated Pulse Template requirements per
Bellcore GR-499-CORE.
For E3 Applications, to further convert this data into an E3 line signal such that each pulse that is generated
by the Transmit E3 LIU block will comply with the ITU-T G.703 Pulse Template requirements for E3
applications.
This particular section will describe the functionality and configuration options of the Transmit DS3/E3 LIU
Block for E3 applications. The functionality and configuration options of the Transmit DS3/E3 LIU Block for
Figure 153 presents a more detailed illustration of the Transmit DS3/E3 LIU Block within the XRT79L71.
FIGURE 152. ILLUSTRATION OF THE FUNCTIONAL BLOCK DIAGRAM OF THE TRANSMIT DIRECTION CIRCUITRY, WHEN-
EVER THE
XRT79L71 HAS BEEN CONFIGURED TO OPERATE IN THE "E3, ITU-T G.751 CLEAR-CHANNEL FRAMER"
MODE (WITH THE "TRANSMIT DS3/E3 FRAMER" BLOCK HIGHLIGHTEDL
Transmit
Payload Data
Input
Interface
Block
Transmit
Payload Data
Input
Interface
Block
Transmit
DS3/E3
Framer
Block
Transmit
DS3/E3
Framer
Block
Tranmit
DS3/E3
LIU Block
Tranmit
DS3/E3
LIU Block
TxSer
TxNib[3:0]
TxInClk
TRING
TTIP
Transmit
Overhead Data
Input Interface
Block
Transmit
Overhead Data
Input Interface
Block
TxOHClk
TxOHIns
TxOHInd
TxOH
TxOHEnable
TxOHFrame
TxNibClk
TxFrame
Tx LAPD
Controller
Block
Tx LAPD
Controller
Block
From Microprocessor
Interface Block
Tx LAPD
Buffer
(90 Bytes)
Tx LAPD
Buffer
(90 Bytes)