The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 28, 1998
Filed:
May. 13, 1996
Donald Bruce Bennett, Apple Valley, MN (US);
Steven Allen Murrphy, Apple Valley, MN (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
The Scalable Coherent Interface (SCI) standard of the Institute of Electrical and Electronics Engineers is intended for fast, high throughput, unidirectional links to high performance microprocessor systems. Key elements of the protocol for SCI include: (a) a 'new/stale' bit which is generated in a data packet for detecting stale packets to discard; (b) a scrubber node in each operational ring of an SCI network which toggles 'new/stale' bits from a 'new' state to a stale state when they are received at the scrubber node. In addition, valid ring identity code bits are used to identify operational rings and target identity code bits are used to identify the intended designated target mode of each packet. Packets are transmitted from input ports to output ports of the switches and through operational rings of the network that are connected until each of the packets reaches a designated target node. Each of the packets includes a 'new/stale' bit which is set to a 'new' state when a packet is generated in a source node in a first operational ring for transmission to a target node in a second operational ring. The target node may be the same as the first node. Scrubber nodes receive the packets and toggles a 'new/stale' bit that is set to a 'new' state to its 'stale' state at the output of the scrubber node. Ring identity code bits at each switch of the input stage are used to identify each of the operational rings. Target identity code bits included in each packet are compared with ring identity code bits that are associated with the input ports of the input stage switches. The 'new/stale' bit of each misrouted packet is reset to a 'new' state which arrives at an input operational stage switch when a comparison of the target identity code bits and the ring identity code bit does not occur, and otherwise the 'new/stale' bit in each packet is left in a stale state if the comparison does occur. The packet is eliminated at the next scrubber node in an operational ring when its 'new/stale' it is in its 'stale' state.