Accuracy-Configurable Radix-4 Adder with a Dynamic Output Modification Scheme

Approximate computing is an efficient approach for reducing computational costs. This method involves a trade-off between computational accuracy and the circuit’s power consumption, delay, and area. However, the accuracy requirements may differ for different applications. In some situations, precise results are required. Therefore, this paper proposes an accuracy-configurable radix-4 adder (ACRA), which uses the power gating technique to turn on or turn off the partial logic gates of an adder element dynamically to compute accurate or approximate results. When the ACRA operates in the approximate mode, the partial sum of one adder element is modified to reduce the error distance between the approximate and accurate results.