EP0119039A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Token access controller protocol and architecture
Assignee: Western Digital Corp
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Filing: 1984-03-02
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Granted: —
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Expires: 2004-03-02
Abstract
Abstract Disclosed is a token access protocol for a local area network and the architecture for a token access controller to implement this protocol. The protocol provides for network initialization, recovery and addition of nodes to the network. The host of each node has a minimal involvement with maintaining the network and the protocol does not require the host processor to format frames for transmission. Data reception or transmission is facilitated through the use of a Direct Memory Access (DMA) so the host processor is freed to perform other tasks while data is being transmitted or received.
Inventors
- 👤 Mark Stieglitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 03:27
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/417
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
349 words
A token access controller for controlling the transmission of information fields over a network comprising a plurality of nodes connected by a transmission medium for transmitting frames, wherein each node has been assigned an unique network address and each node has a token access controller, host processor, memory, and internal bus and interface means to connect said internal bus to said transmission medium, said token access controller comprising: means for passing the right to transmit any information field between nodes, wherein the node that has the right to transmit any information field is the only node that is enabled to transmit on the transmission medium of the network and all other nodes can only be enabled to receive the transmitted frames; means for determining when said token access controller has finished transmitting; means for determining the successor node, wherein the successor node is the node that said token access controller shall pass the token to when said node finishes transmitting and the successor node is unique; means for the host processor of the node of said token access controller to instruct said token access controller where information to be transmitted is stored in the memory of the node of said token access controller; means for transmitting information stored in the memory of the node of said token access controller to another node without the aid of the host processor of the node of said token access controller once said host processor instructs said token access controller of the location of the information in its memory; means for the host processor of the node of said token access controller to instruct said token access controller where information to be received from another node should be stored in the memory of the node of said token access controller; and means for receiving information from another node and storing the information in the memory of the node of said token access controller without the aid of the host processor of the node of said token access controller once said host processor instructs the token access controller where the information should be stored.
Claim 2
Dependent Claim
349 words
A token access controller for controlling the transmission of information fields over a network comprising a plurality of nodes connected by a transmission medium for transmitting frames, wherein each node has been assigned an unique network address and each node has a token access controller, host processor, memory, and internal bus and interface means to connect said internal bus to said transmission medium, said token access controller comprising: means for passing the right to transmit any information field between nodes, wherein the node that has the right to transmit any information field is the only node that is enabled to transmit on the transmission medium of the network and all other nodes can only be enabled to receive the transmitted frames; means for determining when said token access controller has finished transmitting; means for determining the successor node, wherein the successor node is the node that said token access controller shall pass the token to when said node finishes transmitting and the successor node is unique; means for the host processor of the node of said token access controller to instruct said token access controller where information to be transmitted is stored in the memory of the node of said token access controller; means for transmitting information stored in the memory of the node of said token access controller to another node without the aid of the host processor of the node of said token access controller once said host processor instructs said token access controller of the location of the information in its memory; means for the host processor of the node of said token access controller to instruct said token access controller where information to be received from another node should be stored in the memory of the node of said token access controller; and means for receiving information from another node and storing the information in the memory of the node of said token access controller without the aid of the host processor of the node of said token access controller once said host processor instructs the token access controller where the information should be stored.
Claim 3
Dependent Claim
20 words
A token access controller as described in .claim 1, wherein the token access controller is part of said interface means.
Claim 4
Dependent Claim
56 words
A token access controller as described in claim 1 or 2 further including: means for network initialization; means for sending an acknowledgement information field upon receiving an information field wherein said token access controller indicates whether a transmission was received; means for reestablishing the network if the token is lost; and means for eliminating duplicate tokens.
Claim 5
Dependent Claim
135 words
A token access controller as described in claiml, 2 or 3 wherein all information fields are frames transmitted on the transmission medium that start with a flag comprising a unique predefined field and end with a Frame Check Sequence and said flag, said token access controller further including: a receiver comprising means for detecting the flag at the start of the information field, means for verifying whether the Frame Check Sequence is correct, means for informing the token access controller of the result of the Frame Check Sequence, and means for detecting the flag at the end of a frame; and a transmitter comprising means for creating the flag at the start of the information field, means for generating the Frame Check Sequence and means for detecting the flag at the end of the frame.
Claim 6
Dependent Claim
102 words
A token access controller as described in claim 1, 2, 3 or 4 further including: means for central polling of nodes desiring to enter the network, wherein one node transmits a predefined information field over the entire range of addresses of nodes to determine if any nodes want to enter the network; means for distributed polling of nodes desiring to enter the network, wherein each node transmits a . predefined information field over a limited range of addresses to determine if any nodes want to enter the network; means for the host processor to change the successor node to a different node.
Claim 7
Dependent Claim
263 words
A token access protocol for controlling the transmission of information fields over a network, said network comprising a plurality of nodes connected by a transmission medium, wherein each node has a token access controller, a host processor, memory and an internal bus and a network interface to connect the internal bus to the transmission medium, said protocol comprising the following steps: a. assigning to each node an unique network address and an unique next address, wherein the next address of each node is the network address of another node on the network, whereby a logical loop is formed; b. repeatedly passing a right to transmit any information field from the node with said right to transmit to the node that is the next address of the node with the token, wherein the node with the token is the only node on the network that is enabled to transmit information fields on the network to any other node and the node with the token will not pass said right until said node with the token has finished transmitting the information fields; c. monitoring the network for no transmitted fields for a period of time by at least one node, wherein if there are no transmitted fields during that period of time, any node that is monitoring the network can reestablish the network; d. deleting nodes from the network, wherein deleting nodes from the network can be done at any point in the protocol; and e. admitting new nodes onto the network wherein said admitting of new nodes is done by at least one node.
Claim 8
Dependent Claim
263 words
A token access protocol for controlling the transmission of information fields over a network, said network comprising a plurality of nodes connected by a transmission medium, wherein each node has a token access controller, a host processor, memory and an internal bus and a network interface to connect the internal bus to the transmission medium, said protocol comprising the following steps: a. assigning to each node an unique network address and an unique next address, wherein the next address of each node is the network address of another node on the network, whereby a logical loop is formed; b. repeatedly passing a right to transmit any information field from the node with said right to transmit to the node that is the next address of the node with the token, wherein the node with the token is the only node on the network that is enabled to transmit information fields on the network to any other node and the node with the token will not pass said right until said node with the token has finished transmitting the information fields; c. monitoring the network for no transmitted fields for a period of time by at least one node, wherein if there are no transmitted fields during that period of time, any node that is monitoring the network can reestablish the network; d. deleting nodes from the network, wherein deleting nodes from the network can be done at any point in the protocol; and e. admitting new nodes onto the network wherein said admitting of new nodes is done by at least one node.
References Cited (Backward Citations)
No citation records indexed.
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