| 摘要 |
PURPOSE:To keep control functions at a minimum of demand as to the control of a car engine which uses a microcomputer, by detecting the fault of CPU and by performing switching so that data will be supplied from a part except CPU. CONSTITUTION:According to a program stored in ROM which is not shown in the figure, CPU10 reads input data, and performs arithmetic processing to calculate output data. One means 30 among output means is selected via address bus A1, and the output data is supplied from data bus D1 via change-over means 50. If CPU10 is troubled, fault detecting circuit 40 detects that and outputs change-over signal E. Consequently, circuit 50 performs switching operation automatically to select one of signals D2, A2 and C2 from data generating circuit 20, and supplies it to circuit 30. As a result, the control is enabled while the minimum operation of demand as to the control precision of a car, the degree of freedom of the control etc., are maintained. |
