RX VPU: A High-Efficiency Variable-Length Vector Architecture with Widening Reduction MAC for Embedded CNNs. - Ryosuke Higashi; Takeshi Nitta; Akaru Oishi; Kiwamu Takada; Yasuhiro Sugita; Yoichi Yuyama; Hidekazu Bingo; Boyu Tseng; Sugako Otani; Hiroyuki Kondo (COOL CHIPS, 2026)