3Com Corporation

Guy M Chemla

Peter Si-Sheng Wang

The scalability and throughput for high-capacity communication switches is improved by providing a distributed arbitration algorithm which addresses the arbitration inefficiency of prior art systems. Distributed arbitration logic units in each satellite unit in a communication switch execute a protocol for computing a connection map for the switch fabric during each arbitration cycle. The protocol includes a plurality of phases including broadcasting backpressure parameters among the arbitration logic units, generating bids for access to switch fabric resources in each of the arbitration logic units utilizing information shared with other arbitration logic units, broadcasting the results of the bidding process, and configuring the switch fabric using the results.

Distributed switch fabric arbitration

A system of monitoring and protecting integrated circuits against damage due to over temperature conditions functions to monitor the temperature of an IC and either shut down its input clock signal or assert its reset line if case temperatures rise to high. Heat dissipated by an integrated circuit is sensed by a temperature sensor. The temperature sensor is thermally coupled to the integrated circuit via thermal glue or other thermally conductive means. The output of temperature sensor is input to temperature sensor circuitry which converts the low level output of the temperature sensor into a signal that can be read by a processor. The processor is suitable programmed to monitor the output of temperature sensor circuitry. When the temperature of the integrated circuit rises past a predetermined threshold value, the processor outputs a control signal to the clock generator circuitry causing it to switch off its clock signal input by the integrated circuit or asserts the chips reset line. Either action should prevent any further temperature rise of the chip. Other embodiments include monitoring multitude integrated circuits and placing the sensing components within the chip itself. In addition, an embodiment is disclosed that utilizes the JTAG interface standard included in many integrated circuits to transmit temperature information to the processor. In addition, the present invention can be used to generate heat maps of circuit boards, useful during prototyping and in the management of real systems.

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Rosh-Ha′ayin, Israel

Guy M Chemla