Design of Reversible Bidirectional Logarithmic Barrel Shifter

Bit rotation and shifting are two very important operations in many digital logic applications. A barrel shifter can perform rotation and shifting of multiple bits in one cycle. Alternatively, reversible logic is gaining much attention due to its loss-less information processing and low-power dissipation in the logic synthesis. This paper deals with a reversible bi-directional logarithmic barrel shifter that performs rotation of data bits in both the directions. Results establish that the proposed design outperforms the previous designs in terms of quantum cost, number of garbage outputs, hardware cost and the total number of gates. Moreover, the testability feature of the proposed barrel shifter is analyzed with the integer linear program (ILP) method, which reports 7 test vectors of size 6 as a minimal complete test set for single as well as multiple stuck-at faults.