XRT73L03 áç
áçáç
áç
3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.1.0
I
TABLE OF CONTENTS
GENERAL DESCRIPTION ................................................................................................. 1
FEATURES .................................................................................................................................................... 1
APPLICATIONS ......................................................................................................................................... 1
TYPICAL APPLICATIONS ................................................................................................................................. 2
TRANSMIT INTERFACE CHARACTERISTICS: ..................................................................................................... 2
RECEIVE INTERFACE CHARACTERISTICS: ....................................................................................................... 2
ORDERING INFORMATION ............................................................................................... 3
PIN DESCRIPTIONS (BY FUNCTION) .............................................................................. 4
TRANSMIT INTERFACE ................................................................................................................................... 4
RECEIVE INTERFACE ..................................................................................................................................... 6
CLOCK INTERFACE ........................................................................................................................................ 7
OPERATING MODE SELECT ........................................................................................................................... 7
CONTROL AND ALARM INTERFACE ................................................................................................................. 9
MICROPROCESSOR INTERFACE .................................................................................................................... 11
POWER AND GROUND PINS ......................................................................................................................... 13
NOCONNECTION PINS ................................................................................................................................ 14
ELECTRICAL CHARACTERISTICS ................................................................................ 15
ABSOLUTE MAXIMUM RATINGS .................................................................................................................... 21
SYSTEM DESCRIPTION .................................................................................................. 23
THE TRANSMIT SECTION - CHANNELS 0, 1 AND 2 ......................................................................................... 23
THE RECEIVE SECTION - CHANNELS 0, 1 AND 2 ........................................................................................... 23
THE MICROPROCESSOR SERIAL INTERFACE ................................................................................................. 23
1.0 Selecting the Data Rate .................................................................................................................... 24
1.1 CONFIGURING CHANNEL(N) ............................................................................................................................... 24
2.0 The Transmit Section ....................................................................................................................... 26
COMMAND REGISTER, CR4-(N) ...................................................................................................... 26
2.1 THE TRANSMIT LOGIC BLOCK ............................................................................................................................ 26
2.1.1 Accepting Dual-Rail Data from the Terminal Equipment ...................................................................... 26
2.1.2 Accepting Single-Rail Data from the Terminal Equipment ................................................................... 27
COMMAND REGISTER CR1-(N) ....................................................................................................... 27
2.2 THE TRANSMIT CLOCK DUTY CYCLE ADJUST CIRCUITRY ................................................................................... 28
2.3 THE HDB3/B3ZS ENCODER BLOCK .................................................................................................................. 28
2.3.1 B3ZS Encoding .................................................................................................................................... 28
2.3.2 HDB3 Encoding .................................................................................................................................... 29
2.3.3 Disabling the HDB3/B3ZS Encoder ..................................................................................................... 29
COMMAND REGISTER CR2-(N) ....................................................................................................... 30
2.4 THE TRANSMIT PULSE SHAPING CIRCUITRY ....................................................................................................... 30
2.4.1 Enabling the Transmit Line Build-Out Circuit ....................................................................................... 31
COMMAND REGISTER, CR1-(N) ...................................................................................................... 31
2.4.2 Disabling the Transmit Line Build-Out Circuit ....................................................................................... 31
COMMAND REGISTER, CR1-(N) ...................................................................................................... 32
2.4.3 Design Guideline for Setting the Transmit Line Build-Out Circuit ......................................................... 32
2.4.4 The Transmit Line Build-Out Circuit and E3 Applications .................................................................... 32
2.5 INTERFACING THE TRANSMIT SECTIONS OF THE XRT73L03 TO THE LINE ........................................................... 32
TRANSFORMER VENDOR INFORMATION ........................................................................................... 33
3.0 The Receive Section ......................................................................................................................... 33
3.1 INTERFACING THE RECEIVE SECTIONS OF THE XRT73L03 TO THE LINE ............................................................. 33
3.2 THE RECEIVE EQUALIZER BLOCK ...................................................................................................................... 34
3.2.1 Guidelines for Setting the Receive Equalizer ...................................................................................... 35
COMMAND REGISTER CR2-(N) ....................................................................................................... 36
3.3 CLOCK RECOVERY PLL .................................................................................................................................... 36
3.3.1 The Training Mode ............................................................................................................................... 37
3.3.2 The Data/Clock Recovery Mode .......................................................................................................... 37
