UARTE STOPRX on exact byte

[parco]

Hi there,

I'm issuing a STOPRX at a specific time but I'm noticing that more bytes are being put into the buffer from after the STOPRX was issued.

Is there a way to stop the UARTE on the exact byte and process, and receive all bytes from that point on to a different buffer?

Please advise.

UPDATE

After triggering a STOPRX, the UARTE will hang around for a few more bytes, placing them in the same buffer and then calling ENDRX. This is problematic since these new bytes are part of a different message.

Here you can see that STOPRX is triggered during some small idle times, yet the ENDRX doesn't happen till much later.

This results in ENDRX being called with 11, 6 and 1 bytes read (when it should be 6, 6 and 6 bytes read)

[RK]

No. The documentation addresses this. if you're using nRF52 (UARTE so I assume so) up to 4 bytes can be received after the STOPRX task. How many actually are depends on what's on the other end transmitting data to you, if it's slow stopping after the RTS signal is deactivated and keeps sending more data, the UARTE is going to receive it. I assume you're using hardware flow control.

Those bytes however go into the RX FIFO so you can update the memory buffer pointer after you get the ENDRX event and then flush to start those bytes off in your new buffer.

[RK]

ok that's what I'd expect to happen - however reading the original query and all the follow ups, it seems that all 4 bytes end up in the data buffer. or perhaps I've misunderstood what the OP was saying. I would expect that if the EasyDMA transaction is stopped, the very most that would get transferred would be any byte currently being transferred if there is one. That's especially true given this application is just going at 9600 baud.

He definitely says 'more bytes are being put in the buffer', so that sounds like more than one. I got the impression the manual talking about flushing the RX FIFO was in the case the transaction stopped because the data buffer was full, in which case they have nowhere else to go.

I dunno - I haven't tested it - I'm just going on what I read and my interpretation of it.