On Increasing Signal Integrity with Minimal Decap Insertion in Area-Array SoC Floorplan Design

With technology further scaling into deep submicron era, power supply noise become an important problem. Power supply noise problem is getting worse due to serious IR-drop and simultaneous switching noise, and decoupling capacitance (decap) insertion is commonly applied to alleviate the noise. There exist some approaches to addressing this issue, but they suffer either from over-design problem or late decap insertion during design stage. In this paper, we propose a methodology to insert decap in a more efficient and effective way during early design stage in area-array designs. The experimental results are encouraging. Compared with other approaches in [15] and [12], we have inserted enough decap to meet supply noise constraint while others employ more area

Abstraction

While the coverage-driven design validation is getting popular, it would be more convenient for users to have an automatic generator that can generate the input patterns to satisfy the coverage requirements. The symbolic techniques can be used to generate the desired input patterns easily for a specific state transition in a FSM. However, it is not practical for real designs because the memory requirement is often unmanageable. In this paper, we propose an automatic pattern generation engine that can overcome the memory issues for large circuits. It can generate all possible input combinations or notify that such cases will never happen for any specific state transitions. Because we can reasonably partition the HDL designs into the interacting FSM model, the peak memory requirement can be significantly reduced by using the “divide and conquer ” strategy for those small FSMs. The experimental results show that we can indeed generate the required input patterns with reasonable memory requirement for the designs with thousands of registers. 1

Design Planning with 3D-Via Optimization in Alternative Stacking Integrated Circuits

Billions of transistors are placed in one single chip (SoC) with advanced manufacturing technology. Further development is obstructed by the ability to the manufacture of SoC and the signal integrity. Stacking IC is an alternative choice when we design a highperformance high-density chip. Design flow (especially physical design) is facing different issues when compared with 2D IC design. The location of the I/Os seriously affect the number of 3D-Vias and their total area in the stacking IC. This paper proposes a Stacking IC architecture and the corresponding design flow to solve the I/O and 3D-Via problems. In this flow, we have developed a system partition approach to minimize the number of 3D-Vias and balance the I/O number of each tier, and modified one traditional floorplan method to optimize the I/O and module locations. The experimental results are encouraging in the GSRC benchmarks. Compared with greedy and intuitive methods, our framework reduces the number of 3D-Vias by 30.02 % on the average and can balance the I/O count of each tier. The dead space of the final floorplan is reduced by 14.13%