Abstract: A mechanism for isolating failures in a digital system is provided. In one embodiment, a fault table is defined for each unit in the system. Related faults are ordered within the table to reflect the time-order in which the faults would be activated during operation of the associated unit. When multiple related faults are reported for a given unit in the system, the fault that is first located when a linear search of the corresponding fault table is conducted is considered the source of the failure within the unit. If faults are reported for multiple units, the source of the failure for the system is identified using at least one of primary and second priority values assigned to the faults, timestamps obtained when the faults are reported, and an order in which the faults are logged.

Abstract: A mechanism for isolating failures in a digital system is provided. In one embodiment, a fault table is defined for each unit in the system. Related faults are ordered within the table to reflect the time-order in which the faults would be activated during operation of the associated unit. When multiple related faults are reported for a given unit in the system, the fault that is first located when a linear search of the corresponding fault table is conducted is considered the source of the failure within the unit. If faults are reported for multiple units, the source of the failure for the system is identified using at least one of primary and second priority values assigned to the faults, timestamps obtained when the faults are reported, and an order in which the faults are logged.

Abstract: A mechanism for isolating failures in a digital system is provided. In one embodiment, a fault table is defined for each unit in the system. Related faults are ordered within the table to reflect the time-order in which the faults would be activated during operation of the associated unit. When multiple related faults are reported for a given unit in the system, the fault that is first located when a linear search of the corresponding fault table is conducted is considered the source of the failure within the unit. If faults are reported for multiple units, the source of the failure for the system is identified using at least one of primary and second priority values assigned to the faults, timestamps obtained when the faults are reported, and an order in which the faults are logged.

Abstract: A method of and apparatus for improving the efficiency of a data processing system employing multiple dayclocks using the facilities which maintain coherency of the system's level cache memories. These efficiencies result from dedicating a separate individual dayclock to each of the multiple instruction processors within the data processing system thereby decreasing access time and user queuing. These individual dayclocks are each incremented at one microsecond intervals. However, these individual dayclocks require periodic synchronization to avoid system level time-tagging problems. This synchronization occurs at 20 microsecond intervals using the cache coherency maintenance hardware of the system.

Abstract: A method and apparatus for providing for serially transmitting partitioning information between system partitions, and between system partitions and the corresponding data processing resources. Serial transmission may allow the partitioning information to be transmitted using a single I/O ASIC pin, and a single PC board trace. In addition to reducing the required number of I/O ASIC pins and PC board traces, the present invention may increase the overall reliability of the partitioning mechanism.

Abstract: A method and apparatus for providing a multi-source reset for independent partitions within a multiprocessor computer system. In a system having at least two partitions wherein the at least two partitions share interconnect hardware, a reset may be provided to a first one of the at least two partitions while allowing the remaining of the at least two partitions to continue to operate. The interconnect hardware may provide means for reseting a first portion of the interconnect hardware associated with the first partition while allowing the remaining portions of the interconnect hardware to continue to operate undisturbed. The reset function may be triggered by hardware or software in either partition or by a system control facility.

Abstract: A method of and apparatus for efficiently transferring data between a memory system and an instruction processor having a dedicated cache memory. A read request within the instruction processor for a data element not currently stored within the dedicated cache memory creates a read cache miss condition. A transfer of the eight word block containing the requested data element is initiated from the memory system beginning with the 72 bit double word containing the requested data element. The eight word block of data is placed into a block buffer upon being received by the instruction processor. The instruction processor is permitted to resume instruction execution and access to the cache memory as soon as the requested data element has been received by the block buffer. The eight word data block is transferred from the block buffer to cache memory at the next read cache miss condition.