Inventors:
Michael Scott Allen - Austin TX
Ravi Kumar Arimilli - Round Rock TX
John Michael Kaiser - Cedar Park TX
William Kurt Lewchuk - Austin TX
Assignee:
International Business Machines Corporation - Armonk NY
Motorola, Inc. - Schaumburg IL
International Classification:
G06F 1110
Abstract:
A system and method are provided that use a determination of bad data parity and the state of an error signal (Derr. sub. --) as a functional signal indicating a specific type of error in a particular system component. If the Derr. sub. -- signal is active, the parity error recognized by the CPU was caused by a correctable condition in a data providing device. In this instance, the processor will read the corrected data from a buffer without reissuing a fetch request. When the CPU finds a parity error, but Derr. sub. -- is not active a more serious fault condition is identified (bus error or uncorrectable multibit error) requiring a machine level interrupt, or the like. And, when no parity is found by the CPU and Derr. sub. -- is not active, then the data is known to be valid and the parity/ECC latency is eliminated, thereby saving processing cycle time.