Increasing the Utility of Self-Calibration Methods in High-Precision Time Measurement Systems (Abstract Only)

Abstract

Asynchronously operating systems, such as tapped delay lines, are the designer?s favorite, if high resolution and precision in time are required. Their drawback, however, is that they require extensive calibration, which prohibits, among other things, sporadic recalibration during the mode of operation. Recent research has shown that the tight coupling of two selective high-precision systems inside a single FPGA substantially reduces the required calibration time: it was reduced from several hours to about 30 minutes. But even this method has not solved the problem that human intervention is required for selecting suitable calibration points. The research presented in this poster suggests that a hybrid approach is able to solve this problem: rather than tightly coupling two systems, the present approach employs hybrid elements, called X-BOUNCE, that seamlessly incorporate an X-ORCA element into a BOUNCE element. In the practical experiments, X-BOUNCE has reduced the required calibration time from 30 minutes to one second and has abandoned any human intervention. Furthermore, the proposed X-BOUNCE element can be realized by just one FPGA-LUT, which allows for easy scalability. The results were produced on a Cyclone II FPGA that has implemented 200 X-BOUNCE elements. Unfortunately, some elements exhibit a calibration inaccuracy that can be as large as 300 ps.