MEMORY PROTECTION DEVICE, RADIO MOBILE STATION AND RADIO BASE STATION USING MEMORY PROTECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a memory protection device even in the constitution which a program and a constant rewriting under action are stored in the same memory, with protection can be performed partially in the same memory, program area can be protected even when a software runs away.;SOLUTION: The memory protection device with a CPU 1 and an one chip memory 2 has a write signal generation circuit 3 that generates a write memory signal and an external device recognition circuit 4 that can recognize the connection of the external device to the circuit. When the write signal generation circuit 3 recognizes that none of an external device 5 is connected, it sets the address area specified by the circuit for a protection area and does not generate the write memory signal if the CPU 1 tries to write data to the protection area. Consequently, the write signal generation circuit protects the memory by not generating the write signals when it recognizes no external device is connected.;COPYRIGHT: (C)2002,JPO