FDDI network test adapter history store circuit (HSC)
First Claim
1. A history store circuit that provides an interface between a physical (PHY) layer hardware and a memory system to record symbol stream segments received from a fiber optic distributed data interface (FDDI) network, comprising:
- a symbol stream comparator (17) connected to receive an incoming symbol stream from said physical layer hardware for comparing said incoming symbol stream with a symbol trigger sequence received from said FDDI network and for generating a compare output if a match occurs;
history store triggering logic (18,
19) responsive to said compare output from said symbol stream comparator to control symbol stream data storage in said memory system, said history store triggering logic having a plurality of modes of operation; and
a node processor interface (20) connected to said symbol stream comparator and said history store triggering logic for functioning as a control and status interface for a node processor, said node processor for controlling the modes of operation of said history store triggering logic and for reading conditions of said symbol stream comparator, said memory system and said history store triggering logic.
1 Assignment
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Accused Products
Abstract
A History Store Circuit (HSC) is employed with a commercially available FDDI chipset to provide an interface between the PHY layer hardware and a memory system to record symbol stream segments received from the FDDI network. Memory system address and control signals are provided by the HSC. Multiplexor logic is included to support dual-ring network configurations. The HSC provides the electrical interconnection required to interface to the PHY layer hardware so as to allow reception of invalid frames, valid frames, and invalid/valid line state symbol streams from the fiber optic bus. In order to receive such invalid frames and state symbol streams from the fiber optic media, additional logic is provided to allow the user to focus on the segment of network traffic of interest. The HSC includes a Symbol Stream Comparator (SSC) and History Store Triggering Logic (HSTL) to facilitate control of the network traffic segment captured by the HSC. Using this logic, history store capture can be started or stopped based upon receipt of a specific network symbol stream. This allows the user to selectively collect symbol stream data from the network based upon a triggering symbol stream.
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Citations
10 Claims
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1. A history store circuit that provides an interface between a physical (PHY) layer hardware and a memory system to record symbol stream segments received from a fiber optic distributed data interface (FDDI) network, comprising:
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a symbol stream comparator (17) connected to receive an incoming symbol stream from said physical layer hardware for comparing said incoming symbol stream with a symbol trigger sequence received from said FDDI network and for generating a compare output if a match occurs; history store triggering logic (18,
19) responsive to said compare output from said symbol stream comparator to control symbol stream data storage in said memory system, said history store triggering logic having a plurality of modes of operation; anda node processor interface (20) connected to said symbol stream comparator and said history store triggering logic for functioning as a control and status interface for a node processor, said node processor for controlling the modes of operation of said history store triggering logic and for reading conditions of said symbol stream comparator, said memory system and said history store triggering logic. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification