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 motovox scooter parts 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 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 incredibleindiatourtravels.com 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 interfacing methods available as an open-source Python library at https://github.com/Noeloikeau/fpyga.