| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a data communication apparatus, capable of realizing data communication in a high application efficiency state of CPU bus band by reducing the frequency of data movement between units via the CPU bus and reducing the occupied time of the CPU bus, when encrypting or decrypting data, capable of also processing encrypted data by a CPU and capable of realizing data communication with generality, by giving an encryption method with general-purpose properties. <P>SOLUTION: The data communication apparatus is provided with a communication interface 14, a CPU 12 connected to the communication interface 14 via a CPU bus 11 to control communication, a memory 13 for storing data, and an encryptor 15 for encrypting or decrypting data. The memory 13 has a first address space in/from which the CPU 12 can directly write/read out data and a second address space, in/from which the CPU 12 can write/read out data through an encryption processing part 15a as memory spaces. The CPU 12 is constituted so as to select the first address space or the second address space, when are data writtern/read in/from the memory 13. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
