SWIFT: A SWing-reduced interconnect for a Token-based Network-on-Chip in 90nm CMOS

With the advent of chip multi-processors (CMPs), on-chip networks are critical for providing low-power communications that scale to high core counts. With this motivation, we present a 64-bit, 8×8 mesh Network-on-Chip in 90nm CMOS that: a) bypasses flit buffering in routers using Token Flow Control, thereby reducing buffer power along the control path, and b) uses low-voltage-swing crossbars and links to reduce interconnect energy in the data path. These approaches enable 38% power savings and 39% latency reduction, when compared with an equivalent baseline network. An experimental 2×2 core prototype, operating at 400 MHz, validates our design.