AE6 Hardware External Reference Specification

AE6 Hardware External Reference Specification Version 1.0 October, 1986 Richard Hausman Mark Hoke 3Com Corporation 1365 Shorebird Way P.O. Box 7390 Mountain View, California 94039 USA AE6 External Reference Specification Contents Page Introduction 2 Overview Resources 3 Architecture 3 Network Interface Controller 3 Local Memory 3 Address Assignments 4 NIC Register Addresses 5 Technical Specifications NuBus line usage Voltage Tolerance Isolation Voltage Power Dissipation Temperature Variation Humidity Transceiver Selection; BNC Mode External Transceiver Mode Jumper Pin Block BNC Pin Assignments 15 Pin D Connector diagram 15 Pin D Connector signals 6 6 6 6 6 6 7 7 7 7 8 8 Programmatic Guidelines Programmatic Recommendations and Notes 9 Recommended Programming Sequences: Initialization Transmit Receive 10 AE6 Block Diagram 3Com Corporation - Proprietary and Confidential AE6 External Reference Specification 11 12 13 page 1 of 13 10/07/86 AE6 External Reference Specification Contents Page Introduction 2 Overview Resources 3 Architecture 3 Network Interface Controller 3 Local Memory 3 Address Assignments 4 NIC Register Addresses s Technical Specifications NuBus line usage Voltage Tolerance Isolation Voltage Power Dissipation Temperature Variation Humidity Transceiver Selection: BNC Mode External Transceiver Mode Jumper Pin Block BNC Pin Assignments 15 Pin D Connector diagram 15 Pin D Connector signals 6 6 6 6 6 6 7 7 7 7 8 8 Programmatic Guidelines AE6 Programmatic Recommendations and Notes 9 Recommended Programming Sequences: Initialization Transmit Receive 10 11 12 Block Diagram 13 3Com Corporation - Proprietary and Confidential External Reference Specification AE6 page 1 of 13 10/07/86 Introduction; The AE6 is a non-intelligent Ethernet adapter for the Apple NuBus personal computer. It makes use of a 3 chip LAN chipset from National Semiconductor Corp. The 3 chips are a Network Interface Controller (NIC), Serial Network Interface (SNI), and a Coax Transceiver Interface (CTI). This document provides both technical specifications for the adapter card and programatic guidelines specific to the AE6 implementation. The document may be used in conjunction with National's specification document titled DP8390/NS32490 Network Interface Controller (preliminary edition dated July, 1986). 3Com Corporation - Proprietary and Confidential AE6 External Reference Specification page 2 of 13 10/07/86 Qyeryiew Resources; * 16K bytes of RAM * 32K bytes of ROM * Apple NuBus interface * * * on-board 'Thin Net• transceiver multipacket buffering 'Thick Net• tranceiver connection Architecture: The AE6 is a low cost Ethernet adapter designed to provide the Apple PC to Ethernet connection. It supports back to back packet reception with multi-packet buffering using a 16K byte dual ported local memory. The adapter is structured to allow host access for fault isolation. Network Interface Controller: The Netw…