D-tdma data buses with CSMA/CD arbitration bus on wireless 3D IC

Because of the increase in cost for chip fabrication, design-ing a chip family in accordance with the application is be-coming an expensive choice. Wireless 3D IC design offers flexibility to connect known-good-dies selected after chip fabrication. It can stack an arbitrary number of chips at low cost. In this paper, dynamic time division multiple access (D-TDMA) is used for vertical broadcast buses for high communication efficiency of interchip network. However, to implement simple D-TDMA based 3D IC, large area and energy overheads are needed for arbitration since another inductor is needed for sending just several bits as arbitra-tion signal in addition to an inductor for the data transfer. We resolve this problem to employ a carrier sense multiple access with collision detection (CSMA/CD) for arbitration of D-TDMA vertical broadcast buses. Evaluation results show that the proposed bus architecture reduces the num-ber of inductors by 73.6% compared to a simple counter-part which employs D-TDMA based 3D buses. The results also show that an application execution time increases only by 0.3% at most.