A segmented reconfigurable cyclic shifter is proposed in this paper to enable a QC-LDPC decoder to parallelly decode multiple codewords. The proposed shifter can be reconfigured into multiple segments of different sizes. Each segment can perform a cyclic shift of different shift values independently. Therefore, the proposed shifter can enhance the QC-LDPC decoder to decode multiple codewords parallelly by inputting another codeword (or codewords) to re-activate the idle hardware in the traditional design. The test chip of QC-LDPC decoder with the proposed segmented reconfigurable cyclic shifter has been fabricated in 0.18-μm CMOS technology which can parallelly decode six codewords.