Tandem Computers Incorporated

Cupertino, California U.s.a.

Srikumar R Chandran

Mark S Walker

Franco E Mau

Steven A Jan

Error detection of digital data transmitted on an optic link is accomplished by creating, before transmission, a check code comprising check bits that correspond to spaced one of the data bits forming the plurality of bits. The check code is then transmitted with the plurality of bits to a receiver, where the plurality of bits are used to create an error code in the same manner as the check code, the error and check codes compare, and an indication of error generated when a miscompare is detected.

Error detection for fiber distributed interfaced optic link

A digital logic circuit and method for synchronizing the leading edges skewed true-complement signal pair. The circuit is comprised of two similar, interconnected circuit halves, each of which includes three D flip-flop stages. The outputs from the second D flip-flop stages from the two circuit halves are applied to the two inputs of two identical logic gates, such that the signal pair is synchronously transmitted to a pair of output gates through a third D flip-flop stage in each circuit half. The second D flip-flop stages also prevent metastable states from reaching the synchronizer output. Metastable states may result if the input setup time is violated for the first D flip-flop stages. The third D flip-flop stage in each circuit half also eliminates any signal irregularities generated in the logic circuitry from appearing on the synchronizer output lines. The circuit is self-checking in that any single fault in the input signals or in the synchronizer circuit itself will result in the synchronizer output pair not having a true complement relationship.

Growing community of inventors

San Jose, CA, United States of America

Srikumar R Chandran