High-Resolution Waveform Capture Device on a Cyclone-V FPGA

High-Resolution Waveform Capture Device on a Cyclone-V FPGA

Blog Article

We introduce the waveform capture device (WCD), a flexible measurement system capable of recording complex digital signals on trillionth-of-a-second (ps) time scales.The WCD is implemented via modular code on an off-the-shelf field-programmable gate-array (FPGA, Intel/Altera Cyclone V), and incorporates both time-to-digital converter (TDC) and digital storage oscilloscope (DSO) functionality.The device captures a waveform by taking snapshots of a signal as it propagates down an read more ultra-fast transmission line known as a carry chain (CC).It is calibrated via a novel dynamic phase-shifting (DPS) method that requires substantially less data and resources than the state-of-the-art.

Using DPS, we find the measurement resolution - or mean propagation delay from one CC element to the next - to be 4.91±0.04 ps (4.54±0.

02 ps) for a pulse of logic high (low).Similarly, we find the single-shot precision - or mean error on the timing of the waveform - to be 29.52 ps (27.14 ps) for pulses of logic high (low).

We verify these findings by reproducing commercial oscilloscope measurements of asynchronous ring-oscillators on FPGAs, finding the mean pulse width to be 0.240 ± 0.002 ns per inverter gate.Finally, we present a careful analysis of design constraints, introduce a novel error correction algorithm, and sketch a simple extension to the analog domain.

We also provide the Verilog code instantiating our design’s hardware primitives in an Appendix, and make our FPGA nacrack.com interfacing methods available as an open-source Python library at https://github.com/Noeloikeau/fpyga.