I'm troubleshooting my NFCT state machine -- I'm getting a lot of FRAMEDELAYTIMEOUT errors and can't understand why, I'm triggering a TXSTART ASAP... but that's another issue. :)
Thinking maybe the default Window frame is too small, I upped the FRAMEDELAYMAX to 0x80000 in the hopes the FRAMEDELAYTIMEOUT errors might go away.
Well, they haven't, and now I'm routinely getting FRAMESTATUS.RX of 0x10. This bit is not documented in NFCT for the nrf52840 -- so... what does bit 4 in FRAMESTATUS.RX mean?