James M Large

US Patent:

56086628, Mar 4, 1997

Filed:

Jan 12, 1995

Appl. No.:

8/372013

Inventors:

James Large - Wexford PA
Joseph M. Newcomer - Pittsburgh PA
Robert Thibadeau - Pittsburgh PA

Assignee:

Television Computer, Inc. - Pittsburgh PA

International Classification:

G06F 722
H04N 710

US Classification:

36472401

Abstract:

A data processor is connected to a digital communication system such that information packets broadcast on the system are examined to determine if the contents of each packet meet selection criteria, whereupon the packet is coupled to the processor. A state machine or interface processor is connected between the processor and the network, and compares packets to the selection criteria, passing accepted packets and blocking rejected ones. The selection criteria are programmed into the state machine as a decision tree of any length, configuration or data requirements, preferably by the attached data processor, and can include examination of arbitrary sections of the packet for equality/inequality, greater-than/less than, signed and unsigned comparisons and bit mask comparisons. Thus content is variably examined, as opposed to checking for an address or key code at a given byte position. The state machine operates on recognition instructions including byte offset and content specifics.