| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress heat generation and generation of high-frequency noises in a microcomputer or a power supply circuit, in an internal combustion engine controller using the microcomputer. SOLUTION: In this controller, the microcomputer 40 constituting an ECU 30 for controlling an engine is provided with a divider circuit 52 dividing a reference clock to generate a system clock, and a register 'X' 60 storing a division value of the divider circuit 52. Calculation processing executed by a CPU 42 sets a value of the. register 'X' 60 to be small in a high engine speed and to be large in a low engine speed. As a result, a frequency F1 of the system clock can be reduced in the low engine speed not requiring high- speed calculation to suppress a heat generation amount in the microcomputer 40 or the power supply circuit 36 without affecting engine control. In the low engine speed, the generation of the high-frequency noises can be suppressed to suppress malfunction caused by the high-frequency noises.</p> |
