45.6.3.9 Multidrop Mode

If the value 0x6 or 0x07 is written to US_MR.PAR, the USART runs in Multidrop mode. This mode differentiates the data characters and the address characters. Data is transmitted with the parity bit at 0 and addresses are transmitted with the parity bit at 1.

If the USART is configured in Multidrop mode, the receiver sets PARE when the parity bit is high and the transmitter is able to send a character with the parity bit high when a ‘1’ is written to US_CR.SENTA.

To handle parity error, PARE is cleared when a ‘1’ is written to US_CR.RSTSTA.

The transmitter sends an address byte (parity bit set) when US_CR.SENDA = 1. In this case, the next byte written to US_THR is transmitted as an address. Any character written in the US_THR without having written SENDA is transmitted normally with the parity at 0.