Proper LVDS TTL testing process needed

[thomasfire]

ARTIQ Feature Request

Problem this request addresses

For now artiq_sinara_tester doesn't have dedicated test process for the LVDS TTL card, which results in need of continuous reflashing the gateware in order to test all ports, and also needs to be run 4 times each to test different subset of ttls.

Describe the solution you'd like

The least can be done is the ability to choose 4 channels for testing the inputs. Also outputs better be checked simultaneously with inputs, as checks by oscilloscope are hard to conduct properly.

[sbourdeauducq]

continuous reflashing the gateware

How so?
TTLInOut is bidirectional and the direction can be changed at runtime.

[thomasfire]

How so?

I tried switching DIP switches and updating the JSON with regenerated device_db, and it appeared to be not working. Even so, switching DIPs better to be minimized.

[sbourdeauducq]

it appeared to be not working.

Please figure out what is going on.

updating the JSON with regenerated device_db

This sounds like the wrong approach. You need to set 'input' and then call output()/input() in the kernels.