The Research Of Deadline Assignment For End-to-end Tasks In Networks On Chip

As the SoC integrate more functions, bus-based communication has been unable to meet the growing communication needs. In this context, the research and development of Networks-on-Chip (NoC) which can provide higher chip communication performance has become the hot spots of the research for system-on-chip architecture. The current research and application of NoC has begun to take shape. Wormhole switching is a very common communication mechanism on Networks-on-Chip. Due to the characteristics of its communication mechanism, it only needs a small cache space, so that it fits for such Networks-on-Chip system which is strictly limited by cost, power consumption, area. In the paper, we will focus on the research of distributing the deadline for end-to-end tasks on Wormhole-based switching Networks on Chip.In NoC systems, end-to-end real-time task, which consists of a series of tasks and these subtasks are executed in order, requires mutual cooperation of the chip multi-core and on-chip network. Each real-time task has an end-to-end time constraint. Owing to the research of real-time on Networks-on-Chip began comparatively late, so far the research on end-to-end task real-time is blank.The research includes some issues such as the deadline assignment for end-to-end task, the priority assignment for end-to-end task. In the paper, we used two different slot-based time scheduling algorithms, and proposed three heuristic algorithms to calculate all sub-task deadline. In this paper, we tested numerous sets of end-to-end real-time tasks to compare the acceptance rate of three heuristic algorithms with the existing algorithm. The experimental result demonstrates that the three heuristic algorithms we came up with meet the real-time constraints more effectively.