Design-Technology Co-optimization for Cryogenic Tensor Processing Unit

The cryogenic silicon complementary-metal-oxide-semiconductor (CMOS) technology and its application in tensor processing unit (TPU) design are explored. Using the 22 nm fully-depleted-silicon-on-insulator (FDSOI) transistor model that was calibrated at 70 K, this study provides insights into the design/technological knobs to achieve a superior performance at cryogenic temperature (cryo-TPU) by exploiting threshold voltage (Vth) engineering, gain-cell embedded DRAM (GC-eDRAM) and true-single phase clock (TSPC) D flip-flop. Benchmark shows that cryo-TPU using GC-eDRAM based global buffer and TSPC D flip-flop based register surpasses conventional TPU architecture operating at the room temperature: over 33% chip area reduction in iso-power condition, over 94^% power reduction in iso-area condition and over 40% power reduction even when the refrigerator cooling power is included.