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PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
I
TABLE OF CONTENTS
GENERAL DESCRIPTION .................................................................................................................1
Features ............................................................................................................................................................ 1
Applications ..................................................................................................................................................... 1
Ordering Information ............................................................................................................................2
Functional Description .................................................................................................................................... 3
The Receive Section ........................................................................................................................................ 3
The Transmit Section ...................................................................................................................................... 3
The Microprocessor Interface Section .......................................................................................................... 4
Performance Monitor Section ........................................................................................................................ 4
Test and Diagnostic Section .......................................................................................................................... 4
Line Interface Drive and Scan Section .......................................................................................................... 5
FEATURES ....................................................................................................................................................... 6
Transmit and Receive Sections ..................................................................................................................... 6
UTOPIA Interface Blocks ................................................................................................................................... 6
Transmit Cell Processor Block .......................................................................................................................... 7
Receive Cell Processor Block ........................................................................................................................... 7
Transmit PLCP Processor Block ....................................................................................................................... 7
Receive PLCP Processor Block ........................................................................................................................ 7
Transmit/Receive DS3 Framer Block ................................................................................................................ 7
Microprocessor Interface Section ...................................................................................................................... 7
Performance Monitor Section ............................................................................................................................ 8
Test and Diagnostic Section .............................................................................................................................. 8
Line Interface Drive and Scan Section .............................................................................................................. 8
PIN DESCRIPTION ........................................................................................................................................... 9
Absolute Maximum Ratings ...............................................................................................................26
DC ELECTRICAL CHARACTERISTICS ........................................................................................26
AC ELECTRICAL CHARACTERISTICS ........................................................................................26
1.0 SYSTEM DESCRIPTION ...........................................................................................32
System Level Interfacing of the XRT7245 DS3 UNI .......................................................32
Interfacing to the ATM Switch (ATM Layer Processor) .............................................................................. 32
Interfacing to the Local Microprocessor ..................................................................................................... 32
Interfacing the UNI to the DS3 Line ............................................................................................................. 32
Internal Operation of the XRT7245 DS3 UNI device .......................................................34
PRINCIPLE OF OPERATION ..........................................................................................................36
2.0 THE USER NETWORK INTERFACE (UNI) ...............................................................36
3.0 MICROPROCESSOR INTERFACE SECTION AND ON-CHIP PROGRAMMABLE
REGISTERS 38
The Microprocessor Interface Signals ............................................................................38
Interfacing the XRT7245 DS3 UNI to the Local μC/μP Over Via the Microprocessor In-
terface Block .....................................................................................................................40