Accurate Time-to-Digital Converter Based on Xilinx´s Digital Clock Managers

This paper presents an accurate and simple delay measurement method based on Xilinx´s Digital Clock Managers. Particularly, variable phase shift is the modules’ capability exploited in our approach. This method enables the implementation of a time-to-digital converter that achieves a resolution of 200ps on a Xilinx´s Virtex or Spartan-3 FPGA without requiring manual placement & routing, nor an external calibration process. This circuit can be used in any application that demands a precise measurement of a static delay.