XRT7250 Datasheet, PDF (17/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

XRT7250 DS3/E3 FRAMER IC
áç
REV. 1.1.1
Mode 3 Operation) ........................................................................................................................................ 345
Figure 163.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 4 (Nibble-Parallel/Loop-Timed) Operation .................................................. 346
Figure 164.Behavior of the Terminal Interface signals between the XRT7250 and the Terminal Equipment
(Mode 4 Operation) ....................................................................................................................................... 347
Figure 165.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 5 (Nibble-Parallel/Local-Time/Frame-Slave) Operation ............................. 349
Figure 166.Behavior of the Terminal Interface signals between the XRT7250 and the Terminal Equipment (E3
Mode 5 Operation) ........................................................................................................................................ 350
Figure 167.Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Interface
block of the XRT7250 for Mode 6 Operation ................................................................................................ 351
Figure 168.Behavior of the Terminal Interface signals between the XRT7250 and the Terminal Equipment (E3
Mode 6 Operation) ........................................................................................................................................ 352
Figure 169.Simple Illustration of the Transmit Overhead Data Input Interface block .................................... 353
Figure 170.Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input Inter-
face (Method 1) ............................................................................................................................................. 357
Figure 171.Illustration of the signal that must occur between the Terminal Equipment and the XRT7250, in order
to configure the XRT7250 to transmit a Yellow Alarm to the remote terminal equipment ............................. 360
Figure 172.Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input Inter-
face (Method 2) ............................................................................................................................................. 362
Figure 173.Behavior of Transmit Overhead Data Input Interface signals between the XRT7250 and the Terminal
Equipment (for Method 2) ............................................................................................................................. 365
Figure 174.LAPD Message Frame Format ................................................................................................... 366
Figure 175.Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to re-trans-
mit the LAPD Message frame repeatedly at One-Second intervals) ............................................................. 371
Figure 176.Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to transmit
a LAPD Message frame only once). ............................................................................................................. 372
Figure 177.A Simple Illustration of the Transmit E3 Framer Block and the associated paths to other Functional
Blocks ........................................................................................................................................................... 374
Figure 178.Approach to Interfacing the XRT7250 Framer IC device to the XRT7300 DS3/E3/STS-1 LIU ... 377
Figure 179.A Simple Illustration of the Transmit E3 LIU Interface block ....................................................... 378
Figure 180.The Behavior of TxPOS and TxNEG signals during data transmission while the Transmit DS3 LIU
Interface is operating in the Unipolar Mode .................................................................................................. 378
Figure 181.Illustration of AMI Line Code ....................................................................................................... 380
Figure 182.Illustration of two examples of HDB3 Encoding .......................................................................... 380
Figure 183.Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are
configured to be updated on the rising edge of TxLineClk ............................................................................ 382
Figure 184.Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are
configured to be updated on the falling edge of TxLineClk ........................................................................... 382
Figure 185.A Simple Illustration of the Receive Section of the XRT7250, when it has been configured to operate
in the E3 Mode .............................................................................................................................................. 384
Figure 186.A Simple Illustration of the Receive E3 LIU Interface Block ....................................................... 385
Figure 187.Behavior of the RxPOS, RxNEG and RxLineClk signals during data reception of Unipolar Data .....
386
Figure 188.Illustration on how the Receive E3 Framer (within the XRT7250 Framer IC) being interface to
theXRT7300 Line Interface Unit, while the Framer is operating in Bipolar Mode ......................................... 387
Figure 189.Illustration of AMI Line Code ....................................................................................................... 388
Figure 190.Illustration of two examples of HDB3 Decoding .......................................................................... 388
Figure 191.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and Rx-
NEG are to be sampled on the rising edge of RxLineClk ............................................................................. 390
Figure 192.Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and Rx-
NEG are to be sampled on the falling edge of RxLineClk ............................................................................. 390
Figure 193.A Simple Illustration of the Receive E3 Framer Block and the Associated Paths to the Other Func-
tional Blocks .................................................................................................................................................. 391
XV