A novel switchable pin method for regulating power in chip-multiprocessor

Transistor scaling has allowed a large number of circuits to be integrated into integrated circuit (IC) chips implemented in nanometer CMOS technology nodes. However, dark silicon which signifies for under-utilized circuitry will become dominant in future chips due to limited thermal design power (TDP). Furthermore, large voltage loss due to complex routing and placement will also degrade the performance of ICs. In addition, effectively managing power dissipation in a packaged chip is one of the major issues of IC design. Previous work done by our group mainly focused on RCL simulation and elementary IC simulation, this work not only builds on power delivery network (PDN), but also designs switchable pin working for two cores at the layout level. The essence of our idea is to supply power to the chip using traditional I/O pads. In order to balance power supply and I/O bandwidth, we set several groups of parallel switchable pins between the core and memory such that I/O pads can dynamically switch between two modes which are data transmission and power supply. To remove the risk that large current going through I/O pad breaks down the pad frame, we redesigned traditional I/O pad to operate in bi-direction. Using TSMC CMOS 180nm process for the design and simulation, our test results show that the proposed switchable pin can well compensate voltage loss in chip multiprocessor, and transfer time of two modes is very short. For data transmission, we perform a sensitivity study to explore the impact brought by switchable pins. Our simulation results demonstrate that performance degradation is in acceptable range when the switchable pins are added to the chip-multiprocessor.