| 摘要 |
PURPOSE:To contrive the application of hardware for detection of runaway even in a normal mode requiring not extremely high reliability, by providing a normal mode where plural register sets RS are prepared and all RS function as register banks and a protection mode to a 1-chip microcomputer. CONSTITUTION:The gates a5.b7.c10.d12.e15.f17 and g20 are all kept OFF in an initial state of the register write/read actions in a normal mode. Then two register sets RS are selected. The selection of these RS is decided whether the gate a5 or c10 is turned on or not. When a master RS is selected, the gate a5 is turned on and the data 1 is supplied to an RS3. While the gate c10 is turned on and the data 1 is supplied to an RS8 when a protection RS8 is selected. At the same time, the after-data is outputted to an output data bus 2. A coincidence circuit 13 fetches the contents of both RS3 and 8 to decide a coincidence state. Then the signal applying the internal resetting is delivered when no coincidence is obtained. |
