What is "RXD"?

"RXD" stands for "Receive Data" and it is a signal used in serial communication between two devices.

In a typical serial communication setup, one device acts as the transmitter and the other device acts as the receiver. The transmitter sends data to the receiver using a serial data line, while the receiver sends acknowledgement signals to the transmitter using control lines such as CTS and RTS.

The RXD signal is used by the receiver to receive the serial data sent by the transmitter. When the transmitter sends data, it is transmitted one bit at a time on the serial data line, and the receiver reads the bits and reassembles them into a complete message.

The RXD signal is usually an input signal to the receiver, which means that it is connected to a pin or port on the receiver's microcontroller or other processing device. The specific characteristics of the RXD signal, such as its voltage level and timing requirements, can vary depending on the specific communication protocol being used.

RXD is often paired with a "Transmit Data" (TXD) signal, which is used by the transmitter to send data to the receiver. Together, RXD and TXD enable two-way communication between the devices.