TABLE OF CONTENTS
FEATURES ................................................................................................................................................................... 1
GENERAL DESCRIPTION ............................................................................................................................................ 1
PIN CONFIGURATION ................................................................................................................................................. 4
OVERVIEW ................................................................................................................................................................... 5
DESCRIPTION OF PIN FUNCTIONS ........................................................................................................................... 5
BASIC ARCHITECTURE............................................................................................................................................... 8
PROTOCOL DESCRIPTION ....................................................................................................................................... 13
NETWORK PROTOCOL ............................................................................................................................................. 13
DATA RATES .............................................................................................................................................................. 13
NETWORK RECONFIGURATION .............................................................................................................................. 13
BROADCAST MESSAGES ......................................................................................................................................... 15
EXTENDED TIMEOUT FUNCTION ............................................................................................................................ 15
LINE PROTOCOL ....................................................................................................................................................... 15
SYSTEM DESCRIPTION ............................................................................................................................................ 18
MICROCONTROLLER INTERFACE........................................................................................................................... 18
TRANSMISSION MEDIA INTERFACE........................................................................................................................ 18
ARCNET CORE FUNCTIONAL DESCRIPTION ......................................................................................................... 23
MICROSEQUENCER.................................................................................................................................................. 23
INTERNAL REGISTERS ............................................................................................................................................. 23
INTERNAL RAM.......................................................................................................................................................... 35
SOFTWARE INTERFACE........................................................................................................................................... 35
COMMAND CHAINING ............................................................................................................................................... 38
RESET DETAILS......................................................................................................................................................... 40
INITIALIZATION SEQUENCE ..................................................................................................................................... 40
IMPROVED DIAGNOSTICS........................................................................................................................................ 41
COM20051I APPLICATIONS INFORMATION ............................................................................................................ 43
USING ARCNET DIAGNOSTICS TO OPTIMIZE YOUR SYSTEM ............................................................................. 60
CABLING THE COM20051I ........................................................................................................................................ 64
USING THE COM20051I'S EMULATION MODE ........................................................................................................ 65
OPERATIONAL DESCRIPTION.................................................................................................................................. 66
MAXIMUM GUARANTEED RATINGS ........................................................................................................................ 66
DC ELECTRICAL CHARACTERISTICS ..................................................................................................................... 66
TIMING DIAGRAMS.................................................................................................................................................... 68
PACKAGE DIMENSIONS ........................................................................................................................................... 74
SMSC DS – COM20051I
Page 3
Rev. 03/27/2000
SMSC [ SMSC CORPORATION ]
