2021-09-09 10:00 PM
2021-09-09 11:03 PM
As that chip is only a level converter, there are no dedicated CTS/... pins. In general, RTS and TxD a transmitters, while RxD and CTS are receivers, see https://en.wikipedia.org/wiki/RS-232. You may find more info by searching MAX232.
2021-09-12 07:21 PM
Yes. There are no dedicated pins.
ST232BTR is a dual channel transmitters and receivers, used to convert the RX, TX, CTS, RTS signals between TIA/EIA-232 voltage level (can be ±15V) and TTL/CMOS voltage level (3V/5V).
It provides TIA-232 voltage level outputs from a single 5 volt supply by on-chip charge pumps and external capacitors.
Note that the directions are opposite depending on DTE or DCE:
Take a look at STEVAL-PCC001V1 UM. The driver (ST3222EB) being used in the EVB is different, but it provides a reference circuit for the transmitters and receives.