| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a RAM write control device enabling update permission/prohibition of RAM without changing an application program, and an unauthorized access prevention program. <P>SOLUTION: A CPU 8 executes steps of: using an OS to monitor an address shown by a program counter 6; when confirming that the address shown by the program counter 6 transits from a non-guarantee RAM area 11 to a guarantee RAM area 12 in a RAM 5, allowing a program to update the guarantee RAM area 12 in the RAM 5 by using the OS to set an update permission state to a register 7; and when confirming that the address shown by the program counter 6 transits from the guarantee RAM area 12 to the non-guarantee RAM area 11 in the RAM 5, prohibiting the program from updating the guarantee RAM area 12 in the RAM 5 by using the OS to set an update prohibition state to the register 7. <P>COPYRIGHT: (C)2013,JPO&INPIT |
