Low area/power decimal addition with carry-select correction and carry-select sum-digits

We improve a carry-select technique for decimal adders, where pairs of corrective carry-out bits for all decimal positions are computed in parallel. Selection is based on the corresponding positional carry-in bits, which are produced by a quaternary parallel prefix carry network. Carry-out bits select pairs of corrected or intact sum-digits to be later selected by actual carry-in bits at the end of addition process. Analytical evaluation and synthesis results for various hardware sharing architectures on binary, decimal, adders, and subtractors show lower area consumption and less power dissipation of the proposed designs at no additional latency, compared to previous works. (C) 2014 Elsevier B.V. All rights reserved.