Open-Drain Mode Does not Work When TXD Is Configured as Output

When configured as an output, the USART TXD pin can drive the pin high regardless of whether the Open-Drain mode is enabled or not.

Work Around

Configure the TXD pin as an input by writing the corresponding bit in PORTx.DIR to ‘0’ when using Open-Drain mode.

Affected Silicon Revisions

Rev. A3 Rev. A4
X X
Parent topic: USART - Universal Synchronous and Asynchronous Receiver and Transmitter