A 219-μW 1D-to-2D-Based Priority Encoder on 65-nm SOTB CMOS

Priority encoder (PE) is recognized as an indispensable component in the content-addressable memory. In this paper, two efficient architecture of 64-bit PE and 256-bit PE using 1D-array to 2D-array conversion (1D-to-2D) method are presented and implemented in a 65-nm Silicon-on-thin-buried-oxide (SOTB) CMOS process. The 1D-to-2D method is exploited because of its advantages in large-sized PE construction. The SOTB CMOS process is utilized because of its prominent advantages of low-power and high-performance configuration using back bias voltages. The measurement results at 1.2 V showed that a fabricated PE256 chip was fully operational at 45 MHz and consumed approximately 219 μW. Additionally, in sleep mode, the leakage power dropped as low as 0.34 μW at 0.6 V.