topic Re: Lpuart reception problem（S32K144 LPUART） in S32K

Lpuart reception problem（S32K144 LPUART）

ym1 — Thu, 21 May 2020 01:52:26 GMT

Hello everyone!

When I use lpuart，there's a problem:

RX external pull down before initializing lpuart. In this way, the RDRF flag is set and the DATA is 0, that is, a frame value of 0 can be received.

This is very strange, because I think the start bit received by UART should have a falling edge.

PetrS — Thu, 21 May 2020 09:20:26 GMT

Hi,

what is the purpose of RX pull down and what is the connection you have?

UART transceiver should drive RX pin high for idle condition, so pull down has no effect and byte is normally received.

BR, Petr

ym1 — Fri, 22 May 2020 00:37:13 GMT

Hi Petr,

Thank you for your response.

Before UART initialization, I multiplexed RX pin to GPIO, during which RX was pulled down.This is a special function.

2020-05-22