Measurement and Generation of Error Correcting Codes for Package Failures

Error correcting codes have been successfully employed to correct errors associated with failures in computer memories. A typical code which has found wide application is the binary Hamming code. This code corrects single bit errors. With the advent of large-scale integration (LSI) storage array technology, the likelihood of errors which exceed the correction and detection capability of such a code is significant. A serious and heretofore unanswered question is the error detection capability of a given code which is implemented and decoded for single error correction, particularly when a storage array chip or card carrying multiple bits from the codeword has failed. In order to identify this capability, a new reliability parameter called package detectability is defined. This paper also presents a method for computing package detectability. The analysis has been performed on a number of codes in order to optimize the packaging for maximum detectability. In addition, a class of distance 3 codes with maximal b-bit package detectability is given.