Tesing procedures

PulsePins has been designed from the start to allow 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 performing comparisons against the 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, the testing is immediately terminated. A successful completion is reported by printing a message SUCCESS. in green.

One can run the tests continuously using run_all_tests_forever for performing intensive stress testing. The results are collected in /var/volatile for inspection.

Wiring up for testing

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

The image below shows a testing jig. It makes use of 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 configures)
D9	core_clk (PLL output)
D10	int_clk (PLL output)
D11	streamer_qout[0]
D12	streamer_qout[1]

Manual testing

Some test procedures required additional external testing equipement or external wiring.

Multiboard

Random number generator

The built-in rundom 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 SAs with 50ohm input impedance, one can use the 50ohm output driver of the PP_PMOD board).