Uart Buffer Error

[josefgessler]

Hello,

Sometimes I observe a strange behaviour on the UART in the Kinetis using MQX.

When I send a sign, the software (actually the Serial Interrupt in the MQX driver) receives what I sent 4 signs before.

I think that means the other signs are waiting in the FIFO until the next sign is sent.

I can easily reproduce this error when I open in IAR the registers view and let Display the UART registers.

What is happening here? Is there an hardware bug? And how could I solve it?

Thank you for your answers!

[danielchen · Accepted solution]

Hi Josef:

I think you need to check the UART FIFO Receive Watermark (UARTx_RWFIFO) register. This register provides the abillity to set a programmable threshold for notification of the need to remove data from the receiver FIFO/buffer. If you lower this value, it maybe solve this issue.

Regards

Daniel