DESIGN OF A CONFIGURABLE BARREL SHIFTER

Most of general processor chips have a barrel shifter, which performs all kinds of shifter operations in one clock cycle. A new circuit design method is proposed in the paper, which implements a configurable barrel shifter. It can be used as general shifter or alignment shifter. By using the method, the partial decoded barrel shifter is of functions of alignment shifter with additional bits for rounding and general shifter. Based on a few of control logic, the barrel shifter can be reused, and at the same time circuit scale and critical path delay is decreased. In addition, it is easy to use the regular routing is feasible to implement VLSI.