Abstract: In a fully non-intrusive bus monitoring interface the bus under test is not affected at all by the presence of the bus monitor. Other bus devices do not recognize the monitor as it does not participate in the bus arbitration and tree identification. The bus monitor is completely invisible to the bus / devices under test as it is not assigned its own nodeID, does not transmit a SelfID packet and is not affecting the bus topology. Furthermore, the device does not add any delays into the signal propagation between two devices and has neglectable influence on signal quality. However, it still provides the necessary means to tap into the signal transmissions to detect bus symbols and convert them into suitable data patterns for subsequent data analysis.

Abstract: A stealth module is either integrated as hardware logic into or attached as an external module to a bus analyzer, wherein the module electrically and logically isolates the analyzer from the bus being tested whereby the bus being tested is not affected by the presence of the analyzer with respect to bus topology, data transmission, bus bandwidth, and power usage, and furthermore, isolation is single directional so as to allow the analyzer to capture packets on the bus being tested.

Abstract: The preferred embodiment of the present invention provides a data analyzer with a modular bus interface that provides increased flexibility over prior art designs. The modular bus interface allows physical layer devices to be easily swapped, allowing a wide variety of link layer and physical layer device combinations to be tested while minimizing system downtime. In the preferred embodiment, the link layer devices are mounted onto an expansion card that includes a releasable connector. Physical layer devices are mounted onto cards that can plug into the releasable connector. The releasable connector provides the electrical and mechanical connection between the link layer device and the physical layer device, and allows different link layer and physical layer devices to be tested together. By including such a modular bus interface, the preferred embodiment data analyzer provides increased flexibility and performance over prior art systems.