The receiver accepts data when a valid start bit is detected. Each bit following the start bit will be sampled according to the baud rate or XCK clock, and shifted into the receive shift register until the first stop bit of a frame is received. The second stop bit will be ignored by the receiver.
When the first stop bit is received and a complete serial frame is present in the receive shift register, the contents of the shift register will be moved into the two-level or four-level receive buffer. Then, the Receive Complete interrupt flag in the Interrupt Flag Status and Clear register (INTFLAG.RXC) will be set, and the optional interrupt will be generated.
The received data can be read from the DATA register when the Receive Complete interrupt flag is set.