MK02 UART in single-wire mode

[bruceweyrauch]

I want to use the MK02 UART in single-wire mode.  I think understand that this means setting the UART TX PCR  pin registeras a UART Tx pin, and setting the LOOPS and RSRC bits in the UART.  Should the pullups be enabled on the Tx pin?  Is this bit automatically configured as open drain?

[Paul_Tian]

Hi, Bruce

Yes, you are correct. You need to set UART TX PCR to UART function. And enable single wire operation by setting C1[LOOPS] and the receiver source field,

C1[RSRC]. Setting C1[LOOPS] disables the path from the unsynchronized receiver input signal to the receiver. Setting C1[RSRC] connects the receiver input to the output of the TXD pin driver. Both the transmitter and receiver must be enabled (C2[TE] = 1 and C2[RE] = 1).

It is no need to set TX pin pull-up and open drain.

Best Regards

Paul