XRT7250 Datasheet, PDF (14/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

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DS3/E3 FRAMER IC
XRT7250
REV. 1.1.1
174
Figure 66.A Simple Illustration of the Transmit DS3 LIU Interface block ...................................................... 175
Figure 67.The Behavior of TxPOS and TxNEG signals during data transmission while the Transmit DS3 LIU In-
terface is operating in the Unipolar Mode ..................................................................................................... 175
Figure 68.Illustration of AMI Line Code ........................................................................................................ 177
Figure 69.Illustration of two examples of B3ZS Encoding ............................................................................ 177
Figure 70.Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are
configured to be updated on the rising edge of TxLineClk ........................................................................... 179
Figure 71.Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are
configured to be updated on the falling edge of TxLineClk .......................................................................... 179
Figure 72.A Simple Illustration of the Receive Section of the XRT7250, when it has been configured to operate
in the DS3 Mode ........................................................................................................................................... 182
Figure 73.A Simple Illustration of the Receive DS3 LIU Interface Block ...................................................... 183
Figure 74.Behavior of the RxPOS, RxNEG and RxLineClk signals during data reception of Unipolar Data 184
Figure 75.Illustration on how the Receive DS3 Framer (within the XRT7250 Framer IC) being interface to
theXRT7300 Line Interface Unit, while the Framer is operating in Bipolar Mode ......................................... 185
Figure 76.Illustration of AMI Line Code ........................................................................................................ 185
Figure 77.Illustration of two examples of B3ZS Decoding ............................................................................ 186
Figure 78.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and RxNEG
are to be sampled on the rising edge of RxLineClk ...................................................................................... 187
Figure 79.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and RxNEG
are to be sampled on the falling edge of RxLineClk ..................................................................................... 188
Figure 80.A Simple Illustration of the Receive DS3 Framer Block and the Associated Paths to the Other Func-
tional Blocks ................................................................................................................................................. 188
Figure 81.The State Machine Diagram for the Receive DS3 Framer block's Frame Acquisition/Maintenance Al-
gorithm .......................................................................................................................................................... 189
Figure 82.A Simple Illustration of the Locations of the Source, Mid-Network and Sink Terminal Equipment (for
CP-Bit Processing) ....................................................................................................................................... 197
Figure 83.Illustration of the Presumed Configuration of the Mid-Network Terminal Equipment ................... 198
Figure 84.Flow Diagram depicting how the Receive FEAC Processor Functions ........................................ 201
Figure 85.LAPD Message Frame Format ..................................................................................................... 202
Figure 86.Flow Chart depicting the Functionality of the LAPD Receiver ...................................................... 204
Figure 87.A Simple Illustration of the Receive Overhead Output Interface block ......................................... 205
Figure 88.Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output Interface
block (for Method 1). ..................................................................................................................................... 207
Figure 89.Illustration of the signals that are output via the Receive Overhead Output Interface (for Method 1).
210
Figure 90.Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output Interface
block (for Method 2). ..................................................................................................................................... 212
Figure 91.Illustration of the signals that are output via the Receive Overhead Data Output Interface block (for
Method 2). .................................................................................................................................................... 215
Figure 92.A Simple illustration of the Receive Payload Data Output Interface block ................................... 216
Figure 93.Illustration of the XRT7250 DS3/E3 Framer IC being interfaced to the Receive Terminal Equipment
(Serial Mode Operation) ............................................................................................................................... 218
Figure 94.An Illustration of the behavior of the signals between the Receive Payload Data Output Interface block
of the XRT7250 and the Terminal Equipment (Serial Mode Operation) ....................................................... 219
Figure 95.Illustration of the XRT7250 DS3/E3 Framer IC being interfaced to the Receive Section of the Terminal
Equipment (Nibble-Mode Operation) ............................................................................................................ 220
Figure 96.An Illustration of the Behavior of the signals between the Receive Payload Data Output Interface
Block of the XRT7250 and the Terminal Equipment (Nibble-Mode Operation). ........................................... 221
Figure 97.Illustration of the E3, ITU-T G.751 Framing Format. .................................................................... 234
Figure 98.A Simple Illustration of the XRT7250 Transmit Section when it has been configured to operate in the
E3 Mode ....................................................................................................................................................... 235
Figure 99.A Simple Illustration of the Transmit Payload Data Input Interface Block .................................... 236
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