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This paper presents a 256kb 6T static random access memory (SRAM) with threshold power-gating (TPG), low swing global read bit-line (GRBL), and charge-sharing write with Vtrip (VTP) tracking and negative source-line (NVSL) write assists (WA). The TPG facilitates lower NAP mode voltage/power and faster wake-up for the cell array, while low-swing GRBL reduces the dynamic read power. A variation-tolerant charge sharing write scheme, where the floating "Low" global write bit line (GWBL) is used to capacitively couple down the local bit-line (LBL), is combined with a cell Vtrip-tracking and NVSL write assists to improve the write-ability. The 256kb test chip is implemented in UMC 40nm low-power (LP) CMOS technology.Error-free full-functionality is achieved from 1.18GHz at 1.5V to 100MHz at 0.65V without redundancy. The TPG scheme reduces the power by 70% (55%) at 1.5V (0.5V) in NAP mode. The low swing GRBL reduces dynamic read power by 3.5% (8%) at 1.IV (0.65V). The VTP-WA and NVSL-WA improve the write V M1N by 50mV (from 0.7V to 0.65V) and reduce write bit failure rate by 2.75x at 0.65V.

This paper presents a well-structured modified Booth encoding (MBE) multiplier which is applied in the design of a reconfigurable multiply-accumulator (MAC) core. The multiplier adopts an improved Booth encoder and selector to achieve an extra-row-removal and uses a hybrid approach in the two's complementation circuit to reduce the area and improve the speed. The multiplier is used to form a 32-bit reconfigurable MAC core which can be flexibly configured to execute one 32 × 32, two 16 × 16 or four 8 × 8 signed multiply-accumulation. Experimentally, when implemented with a 130 nm CMOS single-V t standard cell library, the multiplier achieved a 15.8% area saving and 11.7% power saving over the classical design, and the reconfigurable MAC achieved a 4.2% area and a 7.4% power saving over the MAC design published so far if implemented with a mixed-V t standard cell library.

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