| abstract |
ABSTRACT In a fault tolerant computer system using dual data processing systems each having dual rails and a single memory for each system, handling errors caused when the memory fails to respond during a memory operation. When the memory fails to respond the system classifies the error as a NXM (nonexistent momory) error. The handling of a NXM error involves distinguishing between three situations, i.e., when the error is detected during boot time sizing of the memory, when the error is due to an invalid address generated by software, and when the error is due to a hardware error in memory. |