RPDN Test Chip
In collaboration with Prof. Alyssa Apsel, we have developed a new approach to integrated voltage regulation based on the concept of reconfigurable power distribution networks (RPDNs) [MICRO'14]. RPDNs allow one switched-capacitor regulator to "borrow" energy storage from regulators associated with underutilized cores resulting in improved area/power efficiency and faster response times. Prof. Alyssa Apsel and her students, with help from students in the Batten Research Group, have recently taped out a test chip in TSMC 65nm meant to illustrate the potential of RPDNs. The above tapeout-ready layout shows how 16 clusters (each containing flyback capacitance and power muxing circuitry) can be combined with four regulator control loops to create variable-area voltage regulators on demand.