A UART receive is truncated

john71 — Wed, 24 Aug 2022 08:17:13 GMT

I work with MKV58F24. When I send a buffer from PC - 128 bytes - I get only 9 on a micro controller side.

I tried a polling method

void UART_RecvPacket() { unsigned char chr; /* If new data arrived. */ if ((kUART_RxDataRegFullFlag | kUART_RxOverrunFlag) & UART_GetStatusFlags(UART0)) { chr = UART0->D; rx_idx++; printf("IDX = %d\n", (int)rx_idx); } }

As well as an interrupt method

void UART0_RX_TX_IRQHandler(void) { unsigned char chr; /* If new data arrived. */ if ((kUART_RxDataRegFullFlag | kUART_RxOverrunFlag) & UART_GetStatusFlags(UART0)) { chr = UART0->D; rx_idx++; printf("IDX = %d\n", (int)rx_idx); } }

The same result - only 9 bytes from 128 are received.

After receiving 9 bytes a status register does not indicates any problem

Set lower baud rate - 9600 (was 115200) - getting a bit more - 17 bytes.

What can be a problem?

OMG. I found the problem - for a debug purpose I used printf a lot in the code. It really slows down and stucks the program flow.

Re: A UART receive is truncated

Robin_Shen — Tue, 23 Aug 2022 11:49:47 GMT

Hi john71,

Looks like you've found the root cause.
Thanks for sharing.

Best Regards,
Robin

topic A UART receive is truncated in Kinetis Microcontrollers

A UART receive is truncated

Re: A UART receive is truncated