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.

[Susheel Nuguru]

Hi,

The manual was written with flow control in mind and I see that the interpretation for the non flow control part is not clear. When the flow control is not enabled, the 4 bytes waiting timeout is still enabled allowing the UARTE to receive 4 bytes. The text that says that the "bytes has to be in succession" is little confusing and I think it should have said that "UARTE will be able to receive upto 4 bytes after STOPRX has been triggered (which is equal to RXTO, still enabled when flow control is not enabled)".

parco, Are you expecting that when you trigger STOPRX you will get ENDRX event immediately? This will not happen even if RXTO is disabled when flow control is not used. This is because when you trigger STOPRX, UARTE could be in the middle of receiving a byte and it will not stop until it receives that byte completely, so according to your protocol you will receive that extra byte anyways. so instead of 7 bytes you might have 8 bytes in your buffer depending on when you triggered STOPRX.