in the "TMC211 / TMC222 FAQ list" you specify:
"Use HW0, HW1 or HW2 (TMC222: HW) input as chip select line to be able to address just one device by SetOTP."
For this purpose, we tied all HW pins to Vbat via 1k and pull them down for chip selection using a bs170 n-FET. As you my guess this does not work as expected.
> When is the state of the HW pin evaluated: only after power up, after some command, continuously?
> Do I have to respect a certain timing? (I already tried really slow)
> Is there an other schematic to accomplish this task?
It would be helpful if your FAQ was a little bit more precise on this topic As this now really costs us money...