| 摘要 |
PURPOSE:To improve the processing reliability of a data compressing/restoring system by deciding whether the data used for the data compressing/restoring processing are normal or wrong. CONSTITUTION:A compressing part 2 receives the data and retrieves a dictionary 3 by an external hash method to compress the input data and to output the coded data. At the same time, a maximum application address holding part 7 holds the maximum value of the address used by the dictionary 3. In a dictionary retrieving state, a comparing part 6 compares the retrieved address value with the address value of the part 7. Then the execution of the normal processing is decided if the retrieved address value is smaller than the maximum application address value. If not, an invalid retrieving state is decided and an error signal is outputted to interrupt the processing under execution. Furthermore the maximum application address value is always updated when the normal processing is carried on and then newly registered in the dictionary 3. |
