topic Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection in S32K

S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

chandan_uv — Tue, 12 Dec 2023 11:43:13 GMT

I want to implement uart flow control but another module only support the CTE<-> CTE and RTE<->RTE connection. I tried checking the example https://community.nxp.com/t5/S32K-Knowledge-Base/S32K-LPUART-hardware-flow-control/ta-p/1116812 but its for CTE<-> RTE and RTE<->CTE. what should I change in the registers setting (TXCTSE, TXRTSE,TXRTSPOL, RXRTSE, TXCTSC) to make it work.

Thanks

Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

VaneB — Wed, 13 Dec 2023 18:03:02 GMT

Hi @chandan_uv

Teoricaly the RTS can support this implementation because the polarity can be changed by TXRTSPOL. Otherwise, CTS can not do this.

But this can be emulated by a GPIO, or you can emulate a UART thought FLEXIO which has support for CST and RTS. This is up to your implementation.

B.R.

VaneB

Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

chandan_uv — Wed, 13 Dec 2023 18:05:57 GMT

@VaneB but only changing polarity will work? bcz in this RTS should be input and CTS should be output. I am confused.

Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

VaneB — Wed, 13 Dec 2023 21:29:14 GMT

Hi @chandan_uv

As I mentioned before RTS can emulate this algorithm, but CTS does not. So, please take into consideration the alternatives I previously mentioned.

Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

chandan_uv — Thu, 14 Dec 2023 05:41:45 GMT

Hi @VaneB, Do you have any example code for this scenario ?

Re: S32k146 UART flow control CTE<-> CTE and RTE<-> RTE connection

VaneB — Thu, 14 Dec 2023 15:51:04 GMT

Hi @chandan_uv

Unfortunately, we do not have any example for this specific scenario, but we have an application note that shows how to emulate a UART using FlexIO. Please check the following link.

Using FlexIO to emulate communications and timing peripherals

Additionally, our recommendation is to emulate the functionality of the underlined in the text of the image provided above with GPIOS. It might be easier for you.