| 摘要 |
PURPOSE:To ensure the effective discrimination for a fixed fault, by providing a means which stores the address information when a 1-bit error occurs and the error bit position information of data and then deciding a fixed fault when the same data exists in the storing means and then deciding an accidental fault if the same data does not exist respectively. CONSTITUTION:A reading data system consists of a memory 1, an error correcting circuit 2, a reading data control circuit 3, a diagnosis register 4 and a selector 5. In addition, the following units are provided: registers 13-15 which store the addresses and syndromes when a 1-bit error occurs, a counter 11 which sets the above-mentioned registers successively with each occurrence of the 1-bit error, a decoder 12, a control circuit consists of AND circuits 8-10 and a timing generating circuit, selectors 16 and 17, a comparator 19, and a discriminating means which decides a fixed fault when a coincident combination of data is obtained from a comparison and decides an accidental fault when no coincident combination of data is obtained. In such constitution, a fixed fault can be effectively detected to ensure the maintenance of a 1-bit error. |
