Testing procedures

PulsePins was designed from the start to support a high degree of internal self-testing. For this reason, the FPGA fabric includes a run-length encoder for reading back the generated stream and comparing it against expected results. These tests are performed with the pptest tool. A collection of shell scripts can be found in the tests/ subdirectory. To start one sweep of the test battery, run run_all_tests. If any error is encountered, testing stops immediately. Successful completion is reported by printing the message SUCCESS.

One can run the tests continuously using run_all_tests_forever to perform intensive stress testing. The main report is written in the current directory as report, and per-test logs are collected under /var/volatile for inspection.

Wiring up for testing

Recommended color coding for connecting the DE10-Nano to a Saleae logic analyzer is provided in the comments in the pulsepins.sv design file.

The image below shows a testing jig. It uses custom cables to connect the logic analyzer to both GPIO ports. Eight bits of qout on the Arduino port are connected to LEDs. An oscilloscope is connected to clock signals on the Arduino port. Some wires for hooking up external clock sources are also visible.

Arduino header

Some signals are additionally brought out on the Arduino header for testing purposes.

Port	Name
D[7:0]	streamer_qout[7:0]
D8	streamer_clk (internal or external, as configured)
D9	core_clk (PLL output)
D10	int_clk (PLL output)
D11	streamer_qout[0]
D12	streamer_qout[1]

Manual testing

Some test procedures require additional external test equipment or external wiring.

Manual board smoke

For a quick hand-run live-board regression check from the repository root, use:

make board-smoke

This is intentionally smaller and faster than run_all_tests: it redeploys the current local board artifacts, reloads the FPGA, runs a few finite pptool checks, and exercises both ppscpi and ppwebgui over the network. Override the target board with TARGETHOST=... if needed.

Multiboard

Random number generator

The built-in random number generator can be tested by running pptest 19. By connecting any of the output pins to a spectrum analyzer, one can examine the whiteness of the spectrum. (For spectrum analyzers with 50 ohm input impedance, one can use the 50 ohm output driver of the PP_PMOD board).