When evaluating the MAX32660 for a project I came across an interesting silicon failure when sending and receiving UART data simultaneously. It seems to be a silicon issue which is not detailed by their errata, and there doesn't seem to be a solution for it, so I wanted to let people know.
Regardless of baudrate, if you start receiving a byte on either UART peripheral, and you simultaneously start to transmit data out of the same peripheral, and the falling edge of the start bit of the transmitted byte falls within the first data bit of the received byte, then the received byte will be corrupted.
I have attached a picture of a Saleae capture to show what I mean. Again, this happens regardless of baudrate and regardless of what UART peripheral you use (UART0 or UART1).
I've already had communications with their technical support which were able to reproduce it, and they have said that they reported it to their application engineers. I haven't gotten a response since.