4.13.5.2.5 Parity Error
Each time a character is received, the receiver calculates the parity of the received data bits, in accordance with the field PAR in the Mode register (DBGU_MR). It then compares the result with the received parity bit. If different, the parity error bit PARE in DBGU_SR is set at the same time RXRDY is set. The parity bit is cleared when DBGU_CR is written with the bit RSTSTA (Reset Status) at 1. If a new character is received before the reset status command is written, the PARE bit remains at 1.