| 摘要 |
PURPOSE:To realize the security protection of stored contents through the simple constitution of a device by providing a ring buffer which is installed between a system bus and a memory and converts data according to bit shift quantity to be set by a prescribed control signal. CONSTITUTION:As for the memory 15, the data is written and read to/from it through the system bus 11 by the control of a processor 13. The ring buffer 17 is installed between the system bus and the memory, and converts the data according to the bit shift quantity to be set by the prescribed control signal. Then, the write-in or the read-out of the data to/from the memory 15 is executed through the ring buffer 17 to which the bit shift quantity of the data is set according to the prescribed control signal. Thus, the conversion of the data is executed through the simple constitution, and the security of the stored contents can be realized. |
