| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an in-vehicle information terminal for sharing data existing in a storage medium with a plurality of CPUs. Ž<P>SOLUTION: A switching control circuit 24 includes a MAILBOX register and a partition register. When one CPU requests a bus right, a value showing a bus right request is written in the MAILBOX register, and a bus right request is made to the other CPU. The other CPU recognizes that the bus right request has been made by referring to the MAILBOX register. When the other CPU changes a partition in any way, a bit corresponding to the changed partition of the partition register is set to 1. Afterwards, the other CPU is notified that an HDD access has been ended by using the MAILBOX register. The CPU which has received the notification checks the partition register to verify a partition updated. Afterwards, the CPU reads the updated data from an HDD as necessary. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
