Calibration of RO-based temperature sensors for a toolset for measuring thermal behavior of FPGA devices

Configurable heat generators for FPGAs

“…The relative performance of the heaters was evaluated by measuring power consumption as well as temperature increase within the FPGA fabric. For that purpose a grid of temperature sensors [5] has been placed among the heaters. Since the steady-state temperature and the dynamic temperature response to a synthetic heat source depend on the ambient conditions, unlike the authors of [4], we value more the power consumption results.…”

“…For automatic placement of heaters we use the toolset previously presented in [5]. The main improvement is that now toolset supports widely used Virtex-5 device family that facilitates direct and fair comparison with other research groups.…”

“…We augment it with a grid of RO-based sensors as described in [5]. We have also used external Pt100 temperature probe connected to Agilent 33410A multimeter.…”

“…To date the best performing heaters in terms of raw power density could be obtained in FPGAs by configuring their Look-Up Tables (LUTs) to operate as a set of 1-stage Ring Oscillators [4,5]. However, RO architecture is sensitive to voltage level changes, which is not the case for synchronous heaters.…”

Hardware microprocessor thermal emulation using synthetic heat sources and temperature sensors in FPGA

“…Our previous effort to automatically calibrate RO-based temperature sensors [15] showed that for Spartan-3 and Spartan-6 devices using a linear function to translate oscillations to temperature was enough. However, for Virtex-5 devices quadratic regression had to be used.…”