Car controlling unit using a multitasking system

摘要

The present invention provides a multi-task system which can suppress the increase of required volume of RAM and which enables a multiplex interruption, and a car controlling unit utilizing that system. A memory area (RAM) utilized in executing a processing is divided into a task area 50 for carrying out a task processing and an interrupt area 60 for carrying out an interrupt processing. An interrupt level is given to the interrupt processing in accordance with its priority. The interrupt area is prepared so that the number thereof is same as that of the interrupt level. This system can suppress the increase of memory areas to be consumed as the interrupt area and can guarantee that all interrupt processings are operated.