Responsive Multithreaded Processor for Distributed Real-Time Systems

Abstract

The Responsive MultiThreaded (RMT) Processor is a system LSI that integrates almost all functions for parallel/distributed real-time systems including robots, intelligent rooms/buildings, ubiquitous computing systems, and amusement systems. Concretely, the RMT Processor integrates real-time processing (RMT Processing Unit), real-time communication (Responsive Link II), computer I/O peripherals (DDR SDRAM I/Fs, DMAC, PCI-X, USB2.0, IEEE1394, etc.), and control I/O peripherals (PWM generators, pulse counters, etc.). The RMT Processor, with a design rule of 0.13<I>μ</I>m CMOS Cu 1P8M and a die size 10.0mm square, was fabricated by TSMC. The RMT Processing Unit (RMT PU) executes eight prioritized threads simultaneously using fine-grained multithreading based on priority, called the RMT architecture. Priority of real-time systems is introduced into all functional units, including cache, fetch, and execution, so the RMT PU guarantees real-time execution of prioritized threads. If resource conflicts occur at functional units, higher priority threads overtake lower priority threads. Flexible powerful vector operation units for multimedia processing are also designed. System designers use on-chip functions easily by connecting required I/Os to this chip and the designers realize distributed control by connecting several RMT Processors with their own functions via Responsive Link II.