Heechun Park

A new trend in system-on-chip (SoC) design is chiplet-based IP reuse using 2.5-D integration. Complete electronic systems can be created through the integration of chiplets on an interposer, rather than through a monolithic flow. This approach expands access to a large catalog of off-the-shelf intellectual properties (IPs), allows reuse of them, and enables heterogeneous integration of blocks in different technologies. In this article, we present a highly integrated design flow that encompasses

A new trend in complex SoC design is chiplet-based IP reuse using 2.5D integration. In this paper we present a highly-integrated design flow that encompasses architecture, circuit, and package to build and simulate heterogeneous 2.5D designs. We chipletize each IP by adding logical protocol translators and physical interface modules. These chiplets are placed/routed on a silicon interposer next. Our package models are then used to calculate PPA and signal/power integrity of the overall system. O

Despite the recent academic efforts to develop Electronic Design Automation (EDA) algorithms for 3D ICs, the current market does not have commercial 3D computer-aided design (CAD) tools. Insteadpseudo-3D alternative design flows have been devised which utilize commercial 2D CAD engines with tricks that help them operate as a fairly-efficient 3D CAD tool. In this paper we provide detailed discussions and fair power-performance-area (PPA) comparisons of state-of-the-art pseudo-3D design flows. We

Interposer-based 2.5-D integrated circuits (ICs) enable the chip-level reuse of hard intellectual properties (IPs), also known as chiplets. Such system-level integration shortens the design cycle considerably for large-scale and heterogeneous chips. Besides traditional interposers, which only provide passive elements and routing, active interposers are furthermore comprised of logic components. When implemented carefully using a dedicated electronic design automation (EDA) flow, an active interp

Monolithic 3D integration provides massive vertical integration through the use of nanoscale inter-layer vias (ILVs). However, high integration density and aggressive scaling of the inter-layer dielectric make ILVs especially prone to defects. We present a low-cost built-in self-test (BIST) method to detect opens, stuck-at faults (SAFs), and bridging faults (shorts) in ILVs. Two test patterns-all-1s and all-0s-are applied to the input side of a set of ILVs (e.g., making up a bus between two tier

Studies have shown that monolithic 3D ( M3D ) ICs outperform the existing through-silicon-via ( TSV ) -based 3D ICs in terms of power, performance, and area ( PPA ) metrics, primarily due to the orders of magnitude denser vertical interconnections offered by the nano-scale monolithic inter-tier vias. In order to facilitate faster industry adoption of the M3D technologies, physical design tools and methodologies are essential. Recent academic efforts in developing an EDA algorithm for 3D ICs, mai

Monolithic 3D IC overcomes the limitation of the existing through-silicon-via (TSV) based 3D IC by providing denser vertical connections with nano-scale inter-layer vias (ILVs). In this paper, we demonstrate a thorough RTL-to-GDS design flow for monolithic 3D IC, which is based on commercial 2D place-and-route (P&R) tools and clever ways to extend them to handle 3D IC designs and simulations. We also provide a low-cost built-in-self-test (BIST) method to detect various faults that can occur on I

Monolithic 3D (M3D) integration provides massive vertical integration through the use of nanoscale inter-layer vias (ILVs). However, high integration density and aggressive scaling of the inter-layer dielectric make ILVs especially prone to defects. We present a low-cost built-in self-test (BIST) method that requires only two test patterns to detect opens, stuck-at faults, and bridging faults (shorts) in ILVs. We also propose an extended BIST architecture for fault detection, called Dual-BIST, t

Recently, deep-learning (DL) models have paid a considerable attention to timing prediction in the placement and routing (P&R) flow. As yet, the DL-based prior works are confined to timing prediction at the time-consuming global routing stage, and very few have addressed the timing prediction problem at the placement, i.e., at the pre-route stage. This is because it is not easy to “accurately” predict various timing parameters at the pre-route stage. Moreover, no work has addressed a seamless li

In through-silicon-via (TSV) based 3-D integrated chips (ICs), synthesizing 3-D clock tree is one of the most challenging tasks. Since the clock signal is delivered to clock sinks (e.g., latches, flip-flops) through TSVs, any fault on a TSV in the clock tree may cause a chip failure. Therefore, ensuring the reliability of clock TSVs in 3-D ICs is highly important. To cope with clock TSV reliability problem effectively, we propose a new circuit cell called slew-controlled TSV fault-tolerant unit

Monolithic 3-D (M3D) technology enables unprecedented degrees of integration on a single chip. The miniscule monolithic intertier vias (MIVs) in M3D are the key behind higher transistor density and more flexibility in designing circuits compared to conventional through silicon via (TSV)-based architectures. This article presents a comprehensive design and test techniques for emerging M3D-enabled circuits and systems.

This work addresses a new structure optimization of neuromorphic computing architectures. This enables to speed up the DNN (deep neural network) computation twice as fast as, theoretically, that of the existing architectures. Precisely, we propose a new structural technique of mixing both of the dendritic and axonal based neuromorphic cores in a way to totally eliminate the inherent non-zero waiting time between cores in the DNN implementation. In addition, in conjunction with the new architectu

Deep learning (DL) models have recently paid considerable attention to timing prediction in the place-and-route (P&R) flow. As yet, the DL-based prior works are confined to timing prediction at the time-consuming routing stage, and very few have addressed the timing prediction problem at the placement, i.e., at the pre-route stage. Moreover, no work has addressed a seamless link of timing prediction at the pre-route stage to the final timing optimization through commercial P&R tools. In this wor

In this paper, we propose a comprehensive physical design flow specifically tailored for Monolithic 3D (M3D) integration, a transformative technology for high-density and highperformance IC design in the post-Moore era. Unlike conventional RTL-to-GDS flows that heavily focus on utilizing commercial 2D design tools, our design flow delves deep into the suboptimal issues inherent in implementing cross-tier connections, which are not adequately addressed by 2D tools. Our proposed flow provides seam

The 2-D CMOS process technology scaling may have reached its pinnacle, yet it is not feasible to manufacture all computing elements at lower technological nodes. This has opened a new branch of chip designing that allows chiplets on different technological nodes to be integrated into a single package using interposers, the passive interconnection mediums. However, establishing a high-frequency communication over an entirely passive layer is one of the significant design challenges of 2.5-D syste