Apparatus and method for enabling a network interface to dynamically assign an address to a connected computer and to establish a virtual circuit with another network interface

• US 5,535,336 A
• Filed: 05/01/1995
• Issued: 07/09/1996
• Est. Priority Date: 09/19/1990
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Kruegeer, William J., Smith, Ralph S.
• Primary Examiner(s): Lee, Thomas G.
• Assistant Examiner(s): BARRY, LANCE LEONARD
• Application Number:
  US08/431,477
• Time in Patent Office: 435 Days
• Field of Search: 340/825.07, 340/825.52, 370/85.4, 370/85.5, 370/85.45, 395/200, 395/275, 395/325, 395/800, 395/200.06, 395/200.1, 395/200.12, 395/200.2, 395/828, 395/829, 395/284
• US Class Current: 709/225
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 12/40013 Details regarding a bus controller
• CPC Class Codes: H04L 12/40169 Flexible bus arrangements arrangements for maintenance or administration involving management of faults; events, alarms H04L41/06; automatic restoration of network faults H04L41/0654
• CPC Class Codes: H04L 12/417 with deterministic access, e.g. token passing
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A network provides the capability for information transfer and resource sharing between a plurality of nodes including computers and peripheral devices. The network is comprised of a plurality of network interfaces coupled together on a network cable in both a daisy chain configuration and a bus configuration. Each node is connected to one of the network interfaces using an interface compatible with each particular node. Each network interface contains logic means for controlling the operation of the network. A means for self-identifying the network address of each node is provided without the need for unique hardware or software in each network interface. One of the network interfaces in the network is self-designated as the network watch dog. The network watch dog performs network error detection and correction. The network provides the capability for nodes to communicate with each other even though their associated interfaces are incompatible. The network also provides a means for performing network protocol conversion necessary in order to allow nodes with incompatible interfaces to communicate. Virtual connections between two nodes may be established whereby uninterrupted information transfer may take place. Particular peripheral devices may be associated with particular computer nodes thereby eliminating the need for a computer node to specify a destination for information transfer. The logic means in each network interface will assign peripheral devices to computers by default.

Claims

1. A computer network interface device for connecting a node with a computer network and providing distributed control of said computer network, said computer network interface device comprising:

a. means for communicating with another computer network interface device using network signals and network commands, said means for communicating including,

i. a network daisy chain interface for use during initialization and self identification of said computer network interface device, and

ii. a network bus interface for performing information transfers over said computer network;

b. a controller for interpreting and responding to said network signals and network commands, said controller coupled to said network daisy chain interface and said network bus interface, said controller further including,

iii. dynamic self-identification means including means for determining a unique address of said computer network interface device in relation to another computer network interface device in said computer network, said means for determining including means for determining if said computer network interface device is a first computer network interface device in said computer network and mean for determining if said computer interface device is a last computer interface device, said first computer network interface device having no other computer network interface device connected to a self-identification input of said network daisy chain interface, said means for determining a unique address referencing said unique address from a dynamically generated address of said first computer network interface device, said dynamic self-identification means further including means for receiving an address of said computer network interface device via said network bus interface as dynamically generated by said another computer network interface device, said computer network interface device further including means for responding only to said network commands having said address dynamically generated by said another computer network interface device,

iv. means for generating a transmit authority command in the form of a token with which said computer network interface obtains the right to transmit data on said computer network via said network bus interface after said address of said computer network interface device has been received by said means for receiving,

v. means for issuing said transmit authority command to any other computer network interface device of said computer network, and

vi. means for interpreting a transmit authority command generated by said any other computer network interface device of said computer network, and

vii. means for granting permission to transmit information on said computer network in response to interpreting said transmit authority command;

viii. means for associating a default destination with the computer network interface device;

ix. means for establishing a virtual circuit between the computer network interface device and a destination when the computer network interface device has the transmit authority

x. means for maintaining the virtual circuit after issuing the transmit authority to another computer network interface device; and

c. a node interface for transferring information between said computer network and said node.

2. The computer network interface device of claim 1 wherein said node interface is a parallel data interface.

3. The computer network interface device of claim 1 wherein said node interface is a serial data interface.

4. The computer network interface device of claim 1 further including watch dog timer means comprising:

means for detecting a failure in said computer network by determining if said transmit authority command has not been received by said computer network interface device for a predetermined timeout period; and

means for correcting a failure in said computer network by re-issuing said transmit authority command.

5. The computer network interface device of claim 1 further including a non-volatile memory for storage of network configuration data and network interface configuration data.

6. The computer network interface device of claim 1 further including means for coupling said computer network interface device to an external power source thereby providing power to said computer network interface device and any other computer network interface device in said computer network.

7. The computer network interface device of claim 1 wherein said network daisy chain interface comprises two conducting connections.

8. The computer network interface device of claim 1 wherein said network bus interface comprises two conducting connections.

9. The computer network interface device of claim 1

wherein the node interface accepts both incoming parallel and serial data.

10. In a computer network interface device having means for connecting a node with a computer network, a process for controlling said computer network interface device comprising the steps of:

dynamically determining a unique address of said computer network interface device in relation to another computer network interface device in said computer network;

determining if said computer network interface device is a first computer network interface device in said computer network, said first computer network interface device having no other computer network interface device connected to a self-identification input of a network daisy chain interface, said determining step further including a step of referencing said unique address from a dynamically generated address of said first computer network interface device;

receiving an address of said computer network interface device via said computer network as dynamically generated by another computer network interface device,

responding only to said network commands having said address dynamically generated by said another computer network interface device;

generating a transmit authority command in the form of a token with which said computer network interface obtains the right to transmit data on said computer network via said network bus interface after said address of said computer network interface device has been received in said receiving step;

issuing said transmit authority command to any other computer network interface device of said computer network;

interpreting a transmit authority command generated by said any other computer network interface device of said computer networks

associating a default destination with the interface if no destination is specified;

granting permission to transmit information on said computer network in response to interpreting said transmit authority command;

establishing a virtual circuit between the computer network interface device and a destination while the computer network interface device has transmit authority; and

maintaining the virtual circuit after issuing the transmit authority to another computer network interface device.

11. The process of claim 10 including a step of receiving parallel data from said node.

12. The process of claim 10 including a step of receiving serial data from said node.

13. The process of claim 10 further including the steps of:

detecting a failure in said computer network by determining if said transmit authority command has not been received by said computer network interface device for a predetermined timeout period; and

correcting a failure in said computer network by re-issuing said transmit authority command.

14. The process of claim 10 further including a step of storing network configuration data and network interface configuration data in a non-volatile memory.

15. The process of claim 10 further including the steps of:

assigning a default destination computer network interface device;

determining if an address of a valid computer network interface device is specified in a network command; and

routing said network command to said default destination computer network interface device if an address of a valid computer network interface device is not specified in said network command.