Purpose and Background of the Research

Building-Block Computing systems enable to build an appropriate system for the target application just by selecting required chips: CPU, memory modules and accelerators and stacking them. Inductive coupling interconnect between chips form a network –on-chip automatically, and a system is optimized even if the specification is not fixed beforehand. For realizing such systems, inter-chip wireless inductive coupling techniques, self-organized network-on-chips, fault tolerant architectures, optimized power control, and a flexible operating system with virtualization facilities are investigated.

Research Methods

For establishment of building-block computing systems, crosscutting researches on circuit, architectures and system software are required. The followings will be investigated in each research field: (1) Although a number of research trials have been reported, the standard design flow of inductive coupling has not been established. Our first goal is developing an IP (Intellectual Property) of inductive coupling interconnect for easy use of the technology. In order to reduce the footprint of inductors, digital circuits must be implemented inside the inductors. Power supply using inductive coupling link is also our challenge. (2) Self-organized network-on-chip which can be formed just by stacking chips will be investigated. (3) Techniques on fault tolerant self optimizing architectures are important to form building-block systems. (4) Power control is essential in 3D chip stacking, since the heat dissipation is difficult. We will use integrated power control techniques from the system software to circuits. (5) A flexible operating system with virtualization technique is needed to integrate all chips into a system.
We will develop the first prototype multi-core system using inductive coupling in 2013. Based on the prototype, techniques on each layer will be investigated. In 2016, we will develop a final system in which various chips can be stacked as shown in Figure 1, and demonstrate our techniques on it.

Expected Research Achievements and Scientific Significance