Barrel shifter circuit having rotation function

Claim 1

An n-bit barrel shifter circuit having a rotation function and connected with a data bus, said circuit comprising: first and second buffer circuits each being connected to said data bus, each of said first and second buffer circuits selectively operating such that one of said buffer circuits operates as an output buffer while another of said buffer circuits operate as an output buffer depending on the number of bits to be shifted in data of n bits; a bidirectional barrel shifter formed by {n×(integer part of n/2+1)} number of transistors and having two inputs coupled to said data bus through said first and second buffer circuits, respectively; and a rightward shift change device and a leftward shift change device respectively connected with said two inputs of said barrel shifter, for controlling one of rightward and leftward shifting depending on the number of bits to be shifted in the data of n bits, said bidirectional barrel shifter receiving a bit control signal group which includes {(an integer part of n/2)+1} number of signals for controlling bit shifting up to (n-1) as the maximum number.