Abstract: Disclosed is a microcomputer such that even when a program cannot be executed in a CPU of the microcomputer due to an external noise, an unstable power-supply voltage, and other causes, and an fatal error such as runaway occurs, returning to the original state is possible within an extremely short time while preferably avoiding initialization of the entire system. During execution of normal software processing, an interrupt signal and a reset signal are output at an arbitrary time, and if it is determined that a CPU of a microcomputer gets into a runaway state, data which has been stored in a RAM as recovery information is read out, and the CPU is recovered to the state before the runaway. Because such recovery from a fatal error occurs within a short time, software which is being executed can continue its processing as if the fatal error had not occurred.

Abstract: Disclosed is an device for restoring information in a main storage unit, wherein, if a malfunction occurs in a microcomputer, the microcomputer is made able to recover from the malfunction. The device comprises: a central processing unit comprising one or more registers; a rewritable first storage unit; a rewritable second storage unit; and storage unit management means. The storage unit management means stores restoration information consisting of storage unit information stored in the first storage unit and register information into the second storage unit, and then the storage unit management means restores the information in the first storage unit and the information in the corresponding one or more registers on the basis of the restoration information stored in the second storage unit.

Abstract: Disclosed is a microcomputer such that even when a program cannot be executed in a CPU of the microcomputer due to an external noise, an unstable power-supply voltage, and other causes, and an fatal error such as runaway occurs, returning to the original state is possible within an extremely short time while preferably avoiding initialization of the entire system. During execution of normal software processing, an interrupt signal and a reset signal are output at an arbitrary time, and if it is determined that a CPU of a microcomputer gets into a runaway state, data which has been stored in a RAM as recovery information is read out, and the CPU is recovered to the state before the runaway. Because such recovery from a fatal error occurs within a short time, software which is being executed can continue its processing as if the fatal error had not occurred.