Abstract: Safety critical systems make more requirements on timeliness and reliability of embedded systems.This paper designed a new kernel for a mixed time-triggered and event-triggered mechanism,meeting the OSEK standard.The kernel has the features of good timeliness,high flexibility and certainty.This paper also put forward a static schedule stra-tegy for mixed tasks and an algorithm to check the schedulability of time-triggered tasks.The flexible switch between tasks at both interrupt and task level helps to guarantee those good features while improving the system utilization as well.The experiment shows that the real-time kernel is effective and efficient with good timeliness and high reliability.

Key words: OSEK/VDX,Time-triggered,Event-triggered,Real-time system