UART byte reception timing

A UART reception timing diagram shows how an asynchronous serial byte is framed on the receive line. The line is idle high, drops for the start bit, carries eight data bits and returns high for the stop bit. Sample points show where a receiver checks each bit, while the busy signal indicates the interval in which the receiver is handling the frame. This compact view helps firmware and hardware engineers confirm a protocol description, explain a logic-analyzer capture or document a test case. Add parity, a second stop bit, baud-rate timing or an error flag when the interface needs them. Keep every signal aligned to the same bit intervals so the framing is unambiguous.