An Accuracy-Improved Fixed-Width Booth Multiplier Enabling Bit-Width Adaptive Truncation Error Compensation

Abstract

Fixed-width Booth multipliers (FWBMs) generate a product with the same bit width as the operand and have been extensively employed in many digital systems. Various truncation error compensation (TEC) schemes have been presented for FWBM designs, aiming to reduce hardware costs while preserving operation accuracy. In general, the existing TEC methods function adequately for an exact bit width of the operand but fail to consider the TEC effect for FWBM inputs with various bit-width levels. To address this issue, we propose a bit-width adaptive TEC (BWATEC) scheme for providing high-accuracy TEC functions that are adaptive to the multiple L′-bit numerical ranges of input data for an L-bit FWBM (L′ ≤ L). We also present adjustable architecture for a 16-bit FWBM to enable the proposed BWATEC scheme and evaluate the hardware performance, using the TSMC 40 nm standard cell library. Relative to the contrast 16-bit FWBM approaches that use state-of-the-art TEC methods, the proposed BWATEC-enabled FWBM design can achieve reductions in the area-delay-error product of 7.9–50.9%, 17.1–69.5%, 29.9–82.2%, and 100% for the 14-bit, 12-bit, 10-bit, and 8-bit inputs, respectively. Moreover, the resultant 16-bit FWBM with BWATEC was verified by using the field-programmable gate array for convolutional neural network acceleration.