System and method for minimizing error correction code bits in variable sized data formats

A method for minimizing ECC bits in variable sized directory formats, comprising:

• obtaining a low order half of a directory entry;
• placing the low order half of the directory entry into a low order half of a common directory representation, the low order half of the directory entry being right justified in the low order half of the common directory representation;
• obtaining a high order half of the directory entry;
• placing the high order half of the directory entry into a high order half of the common directory representation, the high order half of the directory entry being right justified in the high order half of the common directory representation, the high order half of the common directory representation including a plurality of stored ECC bits;
• generating a syndrome for the common directory representation using an ECC matrix;
• detecting errors in the common directory representation in response to the syndrome including any number of “1” bits;
• correcting errors in the common directory representation using the syndrome and the ECC Matrix;
• reformatting the common directory representation into a format of the directory entry.

A system for minimizing ECC bits in variable sized directory formats, comprising:

• a standard directory operable to track memory management information for a multiprocessor computer system with a specified number of processors, the standard directory including one or more data portions and one or more ECC bits;
• a premium directory operable to track memory management information for a multiprocessor computer system with a number of processors exceeding the specified number of processors, the premium directory including one or more data portions and one or more ECC bits;
• a common directory representation operable to provide a common format for performing error detection and correction logic on both the standard directory and the premium directory using a single implementation of the error detection and correction logic, the common directory representation including one or more data portions and one or more ECC bits;
• a common format module operable to format the standard directory into the common directory representation and to fill unused bits of the common directory representation with chosen default values, the chosen default values chosen to provide known values for ECC bit, that are only needed for larger formats represented in the common directory representation thereby minimizing the number of ECC bits stored in a given directory entry format, the common format module further operable to format the premium directory into the common directory representation;
• an error detection and correction module operable to generate a syndrome for the common directory representation using an ECC matrix, the error detection and correction module further operable to detect and correct errors in the common directory representation using the syndrome and the ECC matrix;
• a format module operable to format the error detected and corrected common directory representation into an original directory entry format.