Ok I have this requirement to potentially have 3 x RS232 interface on a board for protocol conversion. I need preferably all 3 interfaces to offer full RS232 V.24 spec with DTR/DSR/DCD as well as the usual RTS/CTS lines. I only see UC3C series (industrial) that offers the full set of pins but only for 1x USART interface.
Any advise? Should I just use the ARM SAMD21 chips (I would prefer) and use its regular RTS/CTS and just put DTR/DSR/DCD in EXTINT pin inputs? I understand the DTR/DSR is just session related stuff. No? What about DCD pin?