UART communications require two pins: Receive Data (RX) and Transmit Data (TX):
- RX (Receive Data): RX is the
serial data input. Glitch filter and oversampling are available.
- TX (Transmit Data): TX is the
serial data output. The TX pin is held high if idling while the module is
enabled. Bidirectional protocols like ISO7816 Smart card can use this pin to
receive data.
The following pins are available in
hardware flow control modes:
- CTS (Clear To Send): This signal
blocks data transmission at the end of the current transfer when driven high by
external signal
- RTS (Request To Send): This
signal indicates the UART is ready to receive data when low.