A Method for Temperature Measurement on Reconfigurable Systems

Thermal verification on reconfigurable systems allow several failures to be detected. Typical problems like configuration errors or bus contention are manifested producing an anomalous chip dissipation. In this work, a fully digital FPGA-oriented temperature monitoring scheme is presented. A control circuit enables a ring-oscillator during a short period and measures their output frequency, a value that is function of the die temperature. Several experiments have been performed using Xilinx 4000 series chips, obtaining sensibilities between 14 kHz per °C and 77 kHz per °C. The main advantage of the proposed method is that neither external transducers nor analog parts are necessary: all the circuits can be constructed using the standard resources of an FPGA. In addition, the complete meter can be dynamically inserted or eliminated of the system.