| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce power consumption necessary for the update operation of an encryption key employed for the coding and decoding of a transmitting information on an internal bus. <P>SOLUTION: Respective bus slaves (6, 7, 8) are provided with first encryption key producing circuits and perform the encoding of an output information to an internal bus (10) (EK1_s, EK2_s EK3_s) and the decoding of an input information. Respective bus masters (2, 12) are provided with a plurality of second encryption key producing circuits (EK1_m, EK2_m, EK3_m), and perform the encoding of the output information to the internal bus and the decoding of the input information employing the encryption key. By an encryption key control circuit (5) and a bus controller (4), the synchronous update of the encryption key is instructed to the first encryption key producing circuit in a group, to which the bus slaves selected as the object of access belong, and a second encryption key producing circuit corresponding to the group. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
