1.8.1 Auto-Baud Overflow

If the baud rate counter overflows before the 5th falling edge is detected, the Auto-Baud Detect Overflow Interrupt Flag (ABDOVF) bit of UxERRIR is set, indicating an overflow condition. An overflow occurs when the 16-bit counter exceeds its maximum size. In this case, the state machine continues to wait for the 5th falling edge to occur on the RX pin. Once the 5th falling edge is detected, hardware sets the Auto-Baud Detect Interrupt Flag (ABDIF) bit of the UART General Interrupt Register (UxUIR) and clears the ABDOVF bit of UxERRIR, while the previous BRG values are retained. To terminate the auto-baud process once an overflow is detected, but before the 5th falling edge is detected, software must first clear the ABDEN bit and then clear the ABDOVF bit.