XRT72L54 Datasheet, PDF (17/484 Pages) Exar Corporation – FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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XRT72L54
FOUR CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
ADVANCED CONFIDENTIAL
REV. P1.1.2
Figure 160. Behavior of the Terminal Interface signals between the XRT72L54 and the Terminal Equipment
(Mode 2 Operation) ............................................................................................................................. 359
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00) ..................................................................... 359
Figure 161. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input In-
terface block of the XRT72L54 for Mode 3 (Serial/Local-Timed/Frame-Master) Operation ................ 360
Figure 162. Behavior of the Terminal Interface signals between the XRT72L54 and the Terminal Equipment
(E3 Mode 3 Operation) ........................................................................................................................ 361
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00) ..................................................................... 361
Figure 163. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input In-
terface block of the XRT72L54 for Mode 4 (Nibble-Parallel/Loop-Timed) Operation .......................... 362
Figure 164. Behavior of the Terminal Interface signals between the XRT72L54 and the Terminal Equipment
(Mode 4 Operation) ............................................................................................................................. 363
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00) ..................................................................... 364
Figure 165. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input In-
terface block of the XRT72L54 for Mode 5 (Nibble-Parallel/Local-Time/Frame-Slave) Operation ..... 365
Figure 166. Behavior of the Terminal Interface signals between the XRT72L54 and the Terminal Equipment
(E3 Mode 5 Operation) ........................................................................................................................ 366
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00) ..................................................................... 366
Figure 167. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input In-
terface block of the XRT72L54 for Mode 6 Operation ......................................................................... 367
Figure 168. Behavior of the Terminal Interface signals between the XRT72L54 and the Terminal Equipment
(E3 Mode 6 Operation) ........................................................................................................................ 368
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00) ..................................................................... 368
6.2.2 The Transmit Overhead Data Input Interface ........................................................................................ 368
Figure 169. Simple Illustration of the Transmit Overhead Data Input Interface block ........................ 369
TABLE 72: A LISTING OF THE OVERHEAD BITS WITHIN THE E3 FRAME, AND THEIR POTENTIAL SOURCES, WITHIN
THE XRT72L54 IC ................................................................................................................................ 370
TABLE 73: DESCRIPTION OF METHOD 1 TRANSMIT OVERHEAD INPUT INTERFACE SIGNALS ..................... 372
Figure 170. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input
Interface (Method 1) ............................................................................................................................ 373
TABLE 74: THE RELATIONSHIP BETWEEN THE NUMBER OF RISING CLOCK EDGES IN TXOHCLK, (SINCE "TXO-
HFRAME" WAS LAST SAMPLED "HIGH") TO THE E3 OVERHEAD BIT, THAT IS BEING PROCESSED ................ 374
Figure 171. Illustration of the signal that must occur between the Terminal Equipment and the XRT72L54,
in order to configure the XRT72L54 to transmit a Yellow Alarm to the remote terminal equipment ... 376
TABLE 75: DESCRIPTION OF METHOD 1 TRANSMIT OVERHEAD INPUT INTERFACE SIGNALS ..................... 377
Figure 172. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input
Interface (Method 2) ............................................................................................................................ 378
TABLE 76: THE RELATIONSHIP BETWEEN THE NUMBER OF TXOHENABLE PULSES (SINCE THE LAST OCCURRENCE
OF THE TXOHFRAME PULSE) TO THE E3 OVERHEAD BIT, THAT IS BEING PROCESSED BY THE XRT72L54 379
Figure 173. Behavior of Transmit Overhead Data Input Interface signals between the XRT72L54 and the
Terminal Equipment (for Method 2) .................................................................................................... 381
6.2.3 The Transmit E3 HDLC Controller ........................................................................................................ 381
Figure 174. LAPD Message Frame Format ....................................................................................... 382
TABLE 77: THE LAPD MESSAGE TYPE AND THE CORRESPONDING VALUE OF THE FIRST BYTE, WITHIN THE INFOR-
MATION PAYLOAD .................................................................................................................................. 382
TRANSMIT E3 LAPD CONFIGURATION REGISTER (ADDRESS = 0X33) ..................................................... 383
TABLE 78: RELATIONSHIP BETWEEN TXLAPD MSG LENGTH AND THE LAPD MESSAGE SIZE .................. 383
TXE3 CONFIGURATION REGISTER (ADDRESS = 0X30) ............................................................................ 384
TXE3 LAPD CONFIGURATION REGISTER (ADDRESS = 0X33) ................................................................. 384
TRANSMIT E3 LAPD CONFIGURATION REGISTER (ADDRESS = 0X33) ..................................................... 384
TXE3 LAPD STATUS AND INTERRUPT REGISTER (ADDRESS = 0X34) ...................................................... 385
TXE3 LAPD STATUS AND INTERRUPT REGISTER (ADDRESS = 0X34) ...................................................... 386
Figure 175. Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to re-
transmit the LAPD Message frame repeatedly at One-Second intervals) ........................................... 387
Figure 176. Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to
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