Sivakumar Velusamy

HotSpot: a compact thermal modeling methodology for early-stage VLSI design

This paper presents HotSpot-a modeling methodology for developing compact thermal models based on the popular stacked-layer packaging scheme in modern very large-scale integration systems. In addition to modeling silicon and packaging layers, HotSpot includes a high-level on-chip interconnect self-heating power and thermal model such that the thermal impacts on interconnects can also be considered during early design stages. The HotSpot compact thermal modeling approach is especially well suited for preregister transfer level (RTL) and presynthesis thermal analysis and is able to provide detailed static and transient temperature information across the die and the package, as it is also computationally efficient.

Compact thermal modeling for temperature-aware design

Thermal design in sub-100nm technologies is one of the major challenges to the CAD community. In this paper, we first introduce the idea of temperature-aware design. We then propose a compact thermal model which can be integrated with modern CAD tools to achieve a temperature-aware design methodology. Finally, we use the compact thermal model in a case study of microprocessor design to show the importance of using temperature as a guideline for the design. Results from our thermal model show that a temperature-aware design approach can provide more accurate estimations, and therefore better decisions and faster design convergence.

Temperature-aware computer systems: Opportunities and challenges

Temperature-aware design techniques have an important role to play in addition to traditional techniques like power-aware design and package- and board-level thermal engineering. The authors define the role of architecture techniques and describe hotspot, an accurate yet fast thermal model suitable for computer architecture research.

Monitoring temperature in FPGA based SoCs

FPGA logic densities continue to increase at a tremendous rate. This has had the undesired consequence of increased power density, which manifests itself as higher on-die temperatures and local hotspots. Sophisticated packaging techniques have become essential to maintain the health of the chip. In addition to static techniques to reduce the temperature, dynamic thermal management techniques are essential. Such techniques rely on accurate on-chip temperature information. In this paper, we present the design of a system that monitors the temperatures at various locations on the FPGA. This system is composed of a controller interfacing to an array of temperature sensors that are implemented on the FPGA fabric. Such a system can be used to implement dynamic thermal management techniques. We cross validate the sensor readings with values obtained from HotSpot, a pre-RTL architectural level thermal modeling tool.

HotSpot: a dynamic compact thermal model at the processor-architecture level

This paper describes a thermal-modeling approach that is easy to use and computationally efficient for modeling thermal effects and thermal-management techniques at the processor architecture level. Our approach is based on modeling thermal behavior of the microprocessor die and its package as a circuit of thermal resistances and capacitances that correspond to functional blocks at the architecture level. This yields a simple compact model, yet heat dissipation within all major functional blocks and the heat flow among blocks and through the package are accounted for. The model is parameterized, boundary- and initial-conditions independent, and is derived by a structure assembly approach. The architecture community has demonstrated growing interest in thermal management, but currently lacks a way to model on-chip temperatures in a tractable way. Our model can be used for initial exploration of the design space at the architecture level. The model can easily be integrated into popular power/performance simulators, can be used to determine how thermal stress is correlated to the architecture, and how architecture-level design decisions influence thermal behavior and related effects.