The inventive control logic provides the selection signals for a bi-endian rotator MUX. The logic determines the starting point for the data transfer by determining which input register byte is going to Byte 0 of the output register. The control logic passes the starting point to single decoder. The decoded value is then sent to a plurality of MUXs, one for each of the output register bytes. Each of the MUXs is prewired to receive a portion of bits of the decoded value, and the portion is arranged in a particular order. The MUXs then send their respective outputs to the rotator MUX as selection control signals.