Properties of Transparent Shortened Codes for Memories With Stuck-at Faults

This correspondence deals with the problem of selecting optimal shortened d = 3 Hamming codes and d = 4 extended Hamming codes. The studied codes are transparent codes, minimum column weight codes, and codes with a minimum number of codewords of minimum weight. It is concluded that a shortened code normally does not combine the properties of being transparent, being of minimum column weight type and having a minimum number of codewords of minimum weight. Furthermore, it is concluded that the weight distribution of a shortened code depends on the selected set of shortened information symbols for a given fixed number of shortened symbols. The correspondence also gives examples of good 22, 16 codes.