| 摘要 |
PURPOSE:To divert the generation of a data error, by providing a circuit to an input terminal of a decoding circuit of an ECC circuit to connect an input to the circuit that gives an optional syndrome bit from a syndrome bit producing circuit. CONSTITUTION:A data is read out of a storage device 10 and stored in a data register 12 along with an ECC. Then an ECC is produced from the data through an ECC producing circuit 14, and a syndrome bit is produced at a syndrome bit producing circuit 16 along with the ECC given from the register 12. The syndrome bit is decoded by a syndrome bit decoding circuit 18, and the data given from the register 12 is corrected to be stored in a storage circuit 10. On the other hand, a switch SW is provided to an input terminal of the circuit 18 to switch an input to a syndrome bit setting circuit 22 that sets an optional syndrome bit. As a result, the switch SW is switched to the circuit 22, and a data error can be produced at a data correcting circuit 20. |
