| 摘要 |
PURPOSE:To find an illegal instruction is executed by writing a specific code at a specific address position, and interrupting a CPU when a program runaway occurs and this code is read out. CONSTITUTION:When memory chips 5 are reset and initialized, the specific code, e.g. code for indicating an internal interruption is written during resetting in the specific address of each memory chip 5 from a code writing circuit 6, and then the chips are initialized after the writing is completed. A program is written in addresses except the addresses wherein said specific code is written. If the program runs away, said specific code is read out and an interruption to the CPU is initiated to detect the runaway of the program. The code of the code writing circuit 6 is not fixed, but set optionally from the outside. |
