Final answer:
UART stands for Universal Asynchronous Receiver Transmitter. The TX line in UART toggles between high and low states. When the TX line is low, it is referred to as the OV state.
Step-by-step explanation:
UART stands for Universal Asynchronous Receiver Transmitter. It is a widely used communication protocol in computers and electronic devices. UART uses a single wire to transmit and receive data, known as the TX (transmit) and RX (receive) lines. The signal on the TX line toggles between high (logic 1) and low (logic 0), representing the binary data being transmitted. When the signal is low, it is known as the OV (over voltage) state.