The overrun bit is not associated with the character in the receive FIFO. The overrun error is set when the FIFO is full, and the next character is completely received in the shift register. The data in the shift register is overwritten, but it is not written into the FIFO. When an empty location is available in the receive FIFO, and another character is received, the state of the overrun bit is copied into the receive FIFO along with the received character. The overrun state is then cleared. The following table lists the bit functions of the receive FIFO.
FIFO bit | Function |
---|---|
11 | Overrun indicator |
10 | Break error |
9 | Parity error |
8 | Framing error |
7:0 | Received data |