| 摘要 |
<p>Duplexing by a program is formed without complicating the program. Surrounding circuits (PER1 to PERn) include registers (REG1 to REGn) and execute processing based on a command. A CPU executes processing by the same program accessing the registers twice. A duplex access control circuit (ACC) includes a peripheral bus access (PBA) part, a buffer (BFF), and a comparison (CMP) part. The PBA part controls access to the registers by the CPU when executing the program for the first time. The BFF memorizes the access information to the registers about the execution of the program for the first time. The CMP part compares access information, about the execution of the program for the second time, with the access information memorized in an access information memorizing part and outputs an error signal to the CPU if the information is not matched with the other one.</p> |
