Will the config tools and LPUART_Init function support inverting the UART polarity?

[rj_engineer]

Hi,

The CTRL register of the MCXA UART contains the TXINV (28) bit which control the polarity of the UART.

However, the config tools doesn't expose this functionnality and the "LPUART_Init" function automatically unset this bit. The only solution found was to disable the RX and TX output (after the "LPUART_Init") to set the TXINV.

LPUART1_PERIPHERAL->CTRL &= ~LPUART_CTRL_TE_MASK;
LPUART1_PERIPHERAL->CTRL &= ~LPUART_CTRL_RE_MASK;
LPUART1_PERIPHERAL->CTRL |= LPUART_CTRL_TXINV_MASK;
LPUART1_PERIPHERAL->CTRL |= LPUART_CTRL_TE_MASK;
LPUART1_PERIPHERAL->CTRL |= LPUART_CTRL_RE_MASK;

This solution cause unnecessary rising edge on the UART lines.

Writing a custom UART init function is overkill and error prone.

The question is :

Is there any other "proper" way to invert the UART polarity and are the config tools scheduled to support this functionnality.

Sincerely,

[Alice_Yang · Accepted solution]

Hi @rj_engineer 

I'm sorry for replying to you late.

1. I have checked the config tool, and it indeed doesn't support this feature. I will submit a feature request to the config tool development team. Thank you

2. We can add this configuration through code, such as

LPUART_CTRL_TXINV(1); // Enable Transmit Data Inversion

Please contact me if still have any question. 

BR

Alice

[rj_engineer]

Thank you for the answer