Receiver Non-Functional after Detection of Inconsistent Synchronization Field

The USART Receiver becomes non-functional when the Inconsistent Synchronization Field Interrupt Flag (ISFIF) in the Status (USARTn.STATUS) register is set.

The ISFIF interrupt flag is set when the Receiver Mode (RXMODE) bit field in the Control B (USARTn.CTRLB) register is configured to Generic Auto-Baud mode (GENAUTO) or LIN Constrained Auto-Baud mode (LINAUTO), and the received synchronization frame does not conform to the conditions described in the data sheet. Clearing the flag does not re-enable the USART Receiver.

Work Around

When the ISFIF interrupt flag is set, disable and re-enable the USART Receiver by first writing a ‘0’ and then a ‘1’ to the Receiver Enable (RXEN) bit in the Control B (USARTn.CTRLB) register.

Affected Silicon Revisions

Rev. C