Responsive Task for Real-Time Communication

Humanoid robots are typical application of real-time systems and have required timing constraints, low-latency, and parallel/distributed processing to achieve fine-grained real-time execution. Therefore, we have developed Dependable Responsive Multithreaded Processor I (D-RMTP I), which has one Responsive Multithreaded Processing Unit with an 8-way prioritized Simultaneous Multithreading architecture. In addition, D-RMTP I has Responsive Link, which is a communication standard as specified in ISO/IEC 24740:2008 for distributed real-time systems. Our previous work presented Responsive Task, which is a low-latency real-time task with the interrupt wake-up structure on D-RMTP I. Unfortunately, Responsive Task does not support real-time communication. We present Responsive Task for real-time communication by using Responsive Link. Responsive Task for real-time communication can be waked up with low-latency by the external interrupt when packets in Responsive Link are received. Experimental results by using Responsive Link show that Responsive Tasks outperform real-time tasks with respect to the overhead of wake-up, the response time, and the jitter.