ThruChip interface (TCI) is an emerging wireless interface in three-dimensional (3-D) integrated circuit (IC) technology. However, the TCI physical design guidelines remain unclear. In this paper, a ThruChip test chip is designed and fabricated for design guidelines exploration. Three inductive coupling interface physical design scenarios, baseline, power mesh, and dummy metal fill, are deployed in the test chip. In the baseline scenario, the test chip measurement results show that thinning chip or enlarging coil dimension can further reduce TCI power. The power mesh scenario shows that the eddy current on power mesh can dramatically reduce magnetic pulse signal and thus possibly cause TCI to fail. A power mesh splitting method is proposed to effectively suppress eddy current impact while minimizing power mesh structure impact. The simulation results show that the proposed method can recover 77% coupling coefficient loss while only introducing additional 0.5% IR-drop. In dummy metal fill case, dummy metal fill enclosed within TCI coils have no impact on TCI transmission and thus are ignorable.

With the advancement of VLSI manufacturing technology, entire electronic systems can be implemented in a single integrated circuit. Due to the complexity in SoC design, circuit testability becomes one of the most challenging works. Without careful planning in Design For Testability (DFT) design, circuits consume more power in test mode operation than that in normal functional mode. This elevated testing power may cause problems including overall yield lost and instant circuit damage. In this paper, we present two approaches to minimize scan based DFT power dissipation. First methodology includes routing cost consideration in scan chain reordering after cell placement, while second methodology provides test pattern compression for lower power. We formulate the first problem as a Traveling Salesman Problem (TSP), with different cost evaluation from, and apply an efficient heuristic to solve it. In the second problem, we provide a selective scan chain architecture and perform a simple yet effective encoding scheme for lower scan testing power dissipation. The experimental results of ISCAS'89 benchmarks show that the first methodology obtains up to 10% average power saving under the same low routing cost compared with a recent result in . The second methodology reduces over 17% of test power compared with filling all don't care (X) bit with 0 in one of ISCAS'89 benchmarks. We also provide the integration flow of these two approaches in this paper.

This paper presents work on integrating wireless 3-D interconnection interface, namely ThruChip Interface (TCI), in three-dimensional field-programmable gate array (3-D FPGA) exploration tool (TPR). TCI is an emerging 3-D IC integration solution because of its advantages over cost, flexibility, reliability, comparable performance, and energy dissipation in comparison to through-silicon-via (TSV). Since the communication bandwidth of TCI is much higher than FPGA internal logic signals, in order to fully utilize its bandwidth, the time-division multiplexing (TDM) scheme is adopted. The experimental results show 25% on average and 58% at maximum path delay reduction over 2-D FPGA when five layers are used in TCI based 3-D FPGA architecture. Although the performance of TCI based 3-D FPGA architecture is 8% below that of TSV based 3-D FPGA on average, TCI based architecture can reduce active area consumed by vertical communication channels by 42% on average in comparison to TSV based architecture and hence leads to better delay and area product.