Low Power, Light Weight and Transparent Multi-Chip Communication Link for IoT Segment

Modern System-on-Chip (SoC) designs requires very high degree of integration at both die and package levels. Multi-Chip Modules (MCM) are very common in these kind of SoCs. One die generally is used to house all the design which are tuned for application oriented compute, wireless sensor and actuator networks. While the second die is used for energy harvesting, power delivery etc. circuits critical to functioning of the Internet-of-Thing (IOT) device. A communication link is required to transfer data between these dies. This link needs to be extremely low gate count, energy efficient without software overhead. But most of the available solutions are tuned for high performance operations. There is no direct solution available for this segment. This paper proposes a light weight, low data rate communication Die-to-Die Simplex Link (D2DSL) for IOT MCM devices. IP connects two dies with a common address map. This makes the accesses to the second die completely transparent with zero software overhead. D2DSL was tested on FPGA, integrated on a test silicon SoC and the performance was fully characterized. The experimental results demonstrate $\sim 3.3\mathrm{x}$ power and $\sim 8\mathrm{x}$ performance improvement for the proposed solution over the existing state of the art solutions for IOT MCM devices.