topic Re: UART suddenly stops receiving data in interrupt mode in MQX Software Solutions

UART suddenly stops receiving data in interrupt mode

panpwr — Sun, 23 Dec 2012 16:46:03 GMT

Hello,

I am using UART3 (ittyd) in interrupt mode (rate of 115200, and buffer size 64 bytes) - K60 and TWR-K60D100M evy board.

I am sampling the port periodically, using fgetc to read the chars and performing _io_fflush at the end of each round.

It works great for a while (around ~50 seconds), and then suddenly stops - nothing comes through.

I've tried increasing the buffer size from 64 bytes to 128 (by changing the BSPCFG_SCI3_QUEUE_SIZE variable in twrk60d100m.h), and it seems that now it works for a longer period - however eventually it still stops receiving data.

What can be the cause for this issue, and how can I approach / debug it?

Thanks,
Lior.

Re: UART suddenly stops receiving data in interrupt mode

panpwr — Mon, 24 Dec 2012 17:43:57 GMT

More information:

When debugging with uVision4, the task that uses the UART state is: "Task Queue Blocked".

I have a suspicion:

Can a bursty traffic fill up the entire buffer, or is it a cyclic buffer? Do I need to clear the buffer each time I finish reading it (how?), or does the new packet runs over the old data in the buffer?

Please, I am desperate here....:smileyconfused:

Re: UART suddenly stops receiving data in interrupt mode

panpwr — Sun, 30 Dec 2012 11:51:44 GMT

OK, it seems that I've figured it out - it was my SW issue (I've been spending too much time in delays rather than in constant UART buffer polling..).