You can acquire digital waveforms on the digital I/O lines. You can configure each digital I/O line to be an output, a static input, or a digital waveform acquisition input.

The digital input waveform acquisition FIFO stores the digital samples. The USB-6421 samples the digital I/O lines on each rising or falling edge of a clock signal, DI Sample Clock.

The following figure summarizes all of the timing options provided by the digital input timing engine.