XRT7250 Datasheet, PDF (16/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

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DS3/E3 FRAMER IC
XRT7250
REV. 1.1.1
Figure 131.Illustration of AMI Line Code ...................................................................................................... 286
Figure 132.Illustration of two examples of HDB3 Decoding ......................................................................... 287
Figure 133.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and Rx-
NEG are to be sampled on the rising edge of RxLineClk ............................................................................. 288
Figure 134.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and Rx-
NEG are to be sampled on the falling edge of RxLineClk ............................................................................ 289
Figure 135.A Simple Illustration of the Receive E3 Framer Block and the Associated Paths to the Other Func-
tional Blocks ................................................................................................................................................. 289
Figure 136.The State Machine Diagram for the Receive E3 Framer E3 Frame Acquisition/Maintenance Algo-
rithm .............................................................................................................................................................. 291
Figure 137.Illustration of the E3, ITU-T G.751 Framing Format ................................................................... 291
Figure 138.Illustration of the Local Receive E3 Framer block, receiving an E3 Frame (from the Remote Termi-
nal) with a correct BIP-4 Value. .................................................................................................................... 299
Figure 139.Illustration of the Local Receive E3 Framer block, transmitting an E3 Frame (to the Remote Termi-
nal) with the “A” bit set to “0” ........................................................................................................................ 300
Figure 140.Illustration of the Local Receive E3 Framer block, receiving an E3 Frame (from the Remote Termi-
nal) with an incorrect BIP-4 value. ................................................................................................................ 301
Figure 141.Illustration of the Local Receive E3 Framer block, transmitting an E3 Frame (to the Remote Termi-
nal) with the “A” bit-field set to “1” ................................................................................................................. 301
Figure 142.LAPD Message Frame Format ................................................................................................... 304
Figure 143.Flow Chart depicting the Functionality of the LAPD Receiver .................................................... 308
Figure 144.A Simple Illustration of the Receive Overhead Output Interface block ....................................... 309
Figure 145.Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output Inter-
face block (for Method 1). ............................................................................................................................. 310
Figure 146.Illustration of the signals that are output via the Receive Overhead Output Interface (for Method 1).
312
Figure 147.Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output Inter-
face block (for Method 2). ............................................................................................................................. 314
Figure 148.Illustration of the signals that are output via the Receive Overhead Data Output Interface block (for
Method 2). .................................................................................................................................................... 315
Figure 149.A Simple illustration of the Receive Payload Data Output Interface block ................................. 316
Figure 150.Illustration of the Terminal Equipment being interfaced to the Receive Payload Data Input Interface
Block of the XRT7250 Framer IC (Serial Mode Operation) .......................................................................... 318
Figure 151.An Illustration of the behavior of the signals between the Receive Payload Data Output Interface
block of the XRT7250 and the Terminal Equipment ..................................................................................... 319
Figure 152.Illustration of the XRT7250 DS3/E3 Framer IC being interfaced to the Receive Section of the Termi-
nal Equipment (Nibble-Parallel Mode Operation) ......................................................................................... 320
Figure 153.Illustration of the signals that are output via the Receive Payload Data Output Interface block (for
Nibble-Parallel Mode Operation). ................................................................................................................. 321
Figure 154.Illustration of the E3, ITU-T G.832 Framing Format. .................................................................. 332
Figure 155.A Simple Illustration of the Transmit Section, within the XRT7250, when it has been configured to
operate in the E3 Mode ................................................................................................................................ 336
Figure 156.A Simple Illustration of the Transmit Payload Data Input Interface Block .................................. 337
Figure 157.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 1 (Serial/Loop-Timed) Operation ............................................................... 340
Figure 158.Behavior of the Terminal Interface signals between the Transmit Payload Data Input Interface block
of the XRT7250 and the Terminal Equipment (for Mode 1 Operation) ......................................................... 341
Figure 159.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 2 (Serial/Local-Timed/Frame-Slave) Operation ......................................... 342
Figure 160.Behavior of the Terminal Interface signals between the XRT7250 and the Terminal Equipment
(Mode 2 Operation) ...................................................................................................................................... 343
Figure 161.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 3 (Serial/Local-Timed/Frame-Master) Operation ....................................... 344
Figure 162.Behavior of the Terminal Interface signals between the XRT7250 and the Terminal Equipment (E3
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