Hello @Avinpat123 ,
Thanks for your post.
According the "66.2.3 External signals" of Reference manual, although FC_P2/FC_P3 can also function as TXD/RXD in LPUART+LPI2C mode, they can only be used as RTS_b/CTS_b in LPUART mode alone. I suspect this is where the issue lies. Are you currently in LPUART mode?

Given this limitation, I recommend switching to PORT4_0 (FC2_P0) and PORT4_1 (FC2_P1) instead. Both pins support alternate functions and can be used as RXD and TXD in LPUART mode of FLEXCOMM2, which aligns with your application requirements.


In addition, if you want try LPUART+LPI2C mode with FC2_P2/FC2_P3 as TXD/RXD, since the config tools do not support configuring a single flexcomm to the LPUART+LPI2C function, I recommend that you refer to our SDK demo "lpflexcomm_interrupt_transfer_cm33".
If you want try LPUART mode only, you can start with "lpuart_polling_cm33_core0" and change the pins via the config tools.
Hope it can help you.
BRs,
Celeste
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