Using error correcting codes for parity purposes

Abstract

Software that provides a subset of error correcting code (ECC) bits to be used for parity purposes. The software performs the following steps: (i) providing, in a data block, a first set of redundant bits adapted to detect and correct errors in the data block, based, at least in part, on a first set of error detection/correction (EDC) requirements; and (ii) providing, within the first set of redundant bits, a first sub-set of parity bit(s) adapted to provide single bit error detection for the data block. The EDC requirements include: (i) a minimum hamming distance, and (ii) the bit(s) in the first set of redundant bits that are not in the first sub-set of parity bit(s) include enough bit(s) to create at least P unique (M-2)-tuples, where P equals the number of bits in the first sub-set of parity bits, and where M equals the minimum hamming distance.

What is claimed is: 
     
         1 . A method comprising:
 providing, in a data block, a first set of redundant bits adapted to detect and correct errors in the data block, based, at least in part, on a first set of error detection/correction (EDC) requirements; and   providing, within the first set of redundant bits, a first sub-set of parity bit(s) adapted to provide single bit error detection for the data block,   wherein the EDC requirements include: (i) a minimum hamming distance representing a minimum number of bits in the data block that must change before the first set of redundant bits is no longer able to detect or correct errors in the data block, and (ii) the bit(s) in the first set of redundant bits that are not in the first sub-set of parity bit(s) include enough bit(s) to create at least P unique (M-2)-tuples, where P equals the number of bits in the first sub-set of parity bits, and where M equals the minimum hamming distance.   
     
     
         2 . The method of  claim 1 , further comprising:
 using the entire first set of redundant bits, including the first sub-set of parity bit(s), to perform error correction or multi-bit error detection for a read operation performed on the data block, without using the first sub-set of parity bit(s) to perform single bit error detection.   
     
     
         3 . The method of  claim 1 , further comprising:
 using the first sub-set of parity bit(s) to perform single bit error detection for a read operation performed on the data block.   
     
     
         4 . The method of  claim 3 , further comprising:
 upon using the first sub-set of parity bit(s) to determine an error in the data block, using the first set of redundant bits to correct the error.   
     
     
         5 . The method of  claim 1 , wherein:
 the EDC requirements further include: (i) a minimum number of bit errors detectable by using the first set of redundant bits, and (ii) a minimum number of bit errors correctable by using the first set of redundant bits.   
     
     
         6 . A computer program product comprising a computer readable storage medium having stored thereon:
 program instructions to provide, in a data block, a first set of redundant bits adapted to detect and correct errors in the data block, based, at least in part, on a first set of error detection/correction (EDC) requirements; and   program instructions to provide, within the first set of redundant bits, a first sub-set of parity bit(s) adapted to provide single bit error detection for the data block,   wherein the EDC requirements include: (i) a minimum hamming distance representing a minimum number of bits in the data block that must change before the first set of redundant bits is no longer able to detect or correct errors in the data block, and (ii) the bit(s) in the first set of redundant bits that are not in the first sub-set of parity bit(s) include enough bit(s) to create at least P unique (M-2)-tuples, where P equals the number of bits in the first sub-set of parity bits, and where M equals the minimum hamming distance.   
     
     
         7 . The computer program product of  claim 6 , further comprising:
 program instructions to use the entire first set of redundant bits, including the first sub-set of parity bit(s), to perform error correction or multi-bit error detection for a read operation performed on the data block, without using the first sub-set of parity bit(s) to perform single bit error detection.   
     
     
         8 . The computer program product of  claim 6 , further comprising:
 program instructions to use the first sub-set of parity bit(s) to perform single bit error detection for a read operation performed on the data block.   
     
     
         9 . The computer program product of  claim 8 , further comprising:
 program instructions to, upon using the first sub-set of parity bit(s) to determine an error in the data block, use the first set of redundant bits to correct the error.   
     
     
         10 . The computer program product of  claim 6 , wherein:
 the EDC requirements further include: (i) a minimum number of bit errors detectable by using the first set of redundant bits, and (ii) a minimum number of bit errors correctable by using the first set of redundant bits.   
     
     
         11 . A computer system comprising:
 a processor(s) set; and   a computer readable storage medium;   wherein:   the processor set is structured, located, connected and/or programmed to run program instructions stored on the computer readable storage medium; and   the program instructions include:
 program instructions to provide, in a data block, a first set of redundant bits adapted to detect and correct errors in the data block, based, at least in part, on a first set of error detection/correction (EDC) requirements; and 
 program instructions to provide, within the first set of redundant bits, a first sub-set of parity bit(s) adapted to provide single bit error detection for the data block, 
 wherein the EDC requirements include: (i) a minimum hamming distance representing a minimum number of bits in the data block that must change before the first set of redundant bits is no longer able to detect or correct errors in the data block, and (ii) the bit(s) in the first set of redundant bits that are not in the first sub-set of parity bit(s) include enough bit(s) to create at least P unique (M-2)-tuples, where P equals the number of bits in the first sub-set of parity bits, and where M equals the minimum hamming distance. 
   
     
     
         12 . The computer system of  claim 11 , wherein the program instructions further include:
 program instructions to use the entire first set of redundant bits, including the first sub-set of parity bit(s), to perform error correction or multi-bit error detection for a read operation performed on the data block, without using the first sub-set of parity bit(s) to perform single bit error detection.   
     
     
         13 . The computer system of  claim 11 , wherein the program instructions further include:
 program instructions to use the first sub-set of parity bit(s) to perform single bit error detection for a read operation performed on the data block.   
     
     
         14 . The computer system of  claim 13 , wherein the program instructions further include:
 program instructions to, upon using the first sub-set of parity bit(s) to determine an error in the data block, use the first set of redundant bits to correct the error.   
     
     
         15 . The computer system of  claim 11 , wherein:
 the EDC requirements further include: (i) a minimum number of bit errors detectable by using the first set of redundant bits, and (ii) a minimum number of bit errors correctable by using the first set of redundant bits.