| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in which readout of confidential data such as a cryptographic key or copy of developed software can be performed, because readout or alteration of a register inside a processor or a local memory is possible from an external bus. <P>SOLUTION: In a media processor which has a bus connected to the outside, all accesses from other devices connected to the external bus are permitted. In order to protect confidential items inside the processor, a TLB is provided in a bus interface unit of the media processor, and the TLB is rewritable only from the inside of the processor. The TLB determines whether or not an externally accessed address can be permitted to access. If access permission is described in the TLB, the access to the inside of the media processor is generated, and if not, the request is canceled. <P>COPYRIGHT: (C)2012,JPO&INPIT |
