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Dropped bytes with K8x LPUART2 when J-Link disconnected

Question asked by Denis Collis on Dec 7, 2017
Latest reply on Dec 11, 2017 by Denis Collis

I have a K8x processor with its LPUART2 connected to an app on a PC.  (fsl_uart driver / 115200-N-8-1)

 

With MCUXpresso running debug via J-Link, the communication channel is robust and reliable.  However, when the debug is terminated, then transmitted bytes (MCU-to-PC) are dropped.  If I remove the J-Link probe, then the same problem occurs.   Received bytes (PC-to-MCU) are good.

 

Serial data is sent using LPUART_WriteBlocking(), which I note has the following ominous warning:

 

 /* This API can only ensure that the data is written into the data buffer but can't
ensure all data in the data buffer are sent into the transmit shift buffer. */ 

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