JP2647908B

PURPOSE:To prevent the destruction of system information due to the run-away of an application program by allocating an address to one side of respective basic input output system programs allocated and stored into a different physical address for rewriting and to other side of them for exclusive use of reading. CONSTITUTION:The title device provides a developing means 10 to develop in parallel the system information to the different physical address of a memory circuit 6, and memory access control means 5a-5f and 1 and 2 to access the system information corresponding to one side physical address for the reading exclusive-use and to access the system information corresponding to other physical address for reading and writing out of the system information developed in parallel to the memory circuit 6 based on the physical address outputted to an address bus 3 connected to the memory circuit 6. Consequently, one side of the same system information can be accessed for the reading exclusive-use and other side can be accessed for writing and reading to the same memory space. Thus, the system information destruction due to the application can be prevented.