An architecture, and a method of utilizing the architecture, have been proposed to enable error-free operation of a data bus that includes, and is connected to, commercial off-the-shelf (COTS) circuits and components that are inherently susceptible to single-event upsets [SEUs (bit flips caused by impinging high-energy particles and photons)]. The architecture and method are applicable, more specifically, to data-bus circuitry based on the Institute for Electrical and Electronics Engineers (IEEE) 1394b standard for a high-speed serial bus.

Two IEEE 1394b Buses would nominally carry identical data signals. The network interface circumvention circuits, with the help of the microcontrollers, would detect radiation-induced upsets on either bus.

The architecture and method call for the use of two IEEE 1394b buses that nominally carry identical data signals. It is assumed that at all times, at least one of the buses is "good" in the sense that it carries complete and correct data signals. Electronic hardware and software operating at each receiving location (node) along the bus would select the data arriving on the "good" bus while ignoring possibly corrupted data arriving on the other bus, which could be operating under latchup or an SEU including, possibly, a single-event functional interrupt (SEFI, an SEU that changes a control logic level, causing the affected circuit to enter an erroneous operational mode or logic state, the recovery from which must be effected through a power reset or other specified procedure).

The hardware at each node would include network-interface circuits plus special-purpose circuits denoted circumvention circuits. Among the circumvention circuits would be bus-management circuits and watchdog timers that would algomonitor the network interface chips. Use of software would examine the outputs of these circumvention monitoring circuits to detect SEUs (including SEFIs). Latchups in radiation-sensitive IEEE 1394b bus components would be detected by current-sensing circumvention circuits. Upon detection of an SEU (including an SEFI) or latchup, other circumvention circuits would restore correct operation by turning off, then turning back on, then reinitializing the affected bus circuitry, all within a predetermined, acceptably short time.

The software would reside in a dedicated radiation-hard microcontroller or shared radiation-hard single-board computer (SBC).

This work was done by Gary A. Kinstler of The Boeing Co. for Marshall Space Flight Center. Title to this invention has been waived under the provisions of the National Aeronautics and Space Act {42 U.S.C. 2457(f)} to The Boeing Co. Inquiries concerning licenses for its commercial development should be addressed to:

The Boeing Co.
5301 Bolsa Ave.
Huntington Beach, CA 92647-2099

Refer to MFS-32132, volume and number of this NASA Tech Briefs issue, and the page number.