RH850, UART, DMA, 1.5Mbps, TX&RX are used together. The receiver will not work after receiving several frames of data. It must be re-initialized, but it will stop working soon, but TX or RX can be used alone.
I guess you still need to include more details in order to fix your issue. However, I suggest you submit a ticket to Renesas Technical Support regarding your issue as information regarding automotive devices is not really shared in public. Also, please use your company email when submitting tickets to Renesas Technical Support. Thank you.
JBRenesasRulz Forum Moderator