TMS570 SCI DMA detection of frame byte

Constantin Wiesener

Hi,

we are building up a RS485 connection between two processors using two RS485 transceivers. For a RS485 it is necessary to set the direction line since it is only half duplex (to avoid collision).

Therefore we would like to send a data frame via DMA to the SCI TD Register if a certain byte has been received at the DMA from the RD Register of the SCI indicating that a frame has been received.

Kiind regards,

C.W.

over 11 years ago

0 Brian Fortman over 11 years ago

TI__Expert 7650 points

Hi C.W.,

We have received your post.

Can you please confirm that you plan to have the CPU snoop the bytes received looking for your RX'd value match?

0 Constantin Wiesener over 11 years ago in reply to Brian Fortman

Intellectual 540 points

Correct:

e.g. I have a frame like <STX><..........><ETX>
and I want the DMA to trigger an interrupt or to transmit one frame if the <ETX> byte has been notified at the RD register of the SCI module.

Kind regards,

C.W.

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TMS570 SCI DMA detection of frame byte