Detect SCI busy or complete

ItKo

I am trying to check for a busy SCI bus so I don't send or receive data while there is an ongoing communication. However, I don't see any way for me to check for a completed communication. As far as I'm aware the IDLE and BUSY bits only apply to the Rx line. Is there any register that can be used to detect any ongoing SCI communication?

I can use my own flag system which is set and reset in the interrupt handlers. But I would much rather use a register if possible.

over 10 years ago

0 Anthony F. Seely over 10 years ago

TI__Guru 68920 points

Itto,

So are you asking if there is any status bit that indicates that the SCI is currently transmitting then?

0 ItKo over 10 years ago in reply to Anthony F. Seely

Prodigy 215 points

Ideally, a bit to indicate if the SCI is currently transmitting OR receiving. However, even a bit that just indicates transmission would be fine. Does any such register exist?

0 Anthony F. Seely over 10 years ago in reply to ItKo

TI__Guru 68920 points

Itto,

You can try to use the TXEMPTY flag to determine if your transmitter is busy. It's set when both the buffer and shift register is empty which implies that the transmitter is idle. Like you mentioned there are other bits for RX.

If you are looping back the transmit to receive through a half-duplex transceiver you can probably get away with just monitoring RX idle, and you'll receive back anything you transmit.