SCI DMA RX and TX

Giorgio Guglielmino

Hello,

For my understanding, I have to chain 2 DMA channels for SCI RX in order to force the WCP RAM to be updated which only occurs when the DMA channels changes.

I would like to use both DMA for RX and TX, but in this case, i have no DMA channels available for TX.

How could I solve this issue?

Could I use the same channel for both RX and TX? but in this way, I'm probably going to have a lot of issues.

Thanks for your help

Giorgio

over 6 years ago

0 Miro over 6 years ago

TI__Mastermind 21425 points

Hi Giorgio,
Which device are you using?

Best regards,
Miro

0 Giorgio Guglielmino over 6 years ago in reply to Miro

Prodigy 235 points

Hi Miro,

RM48L952ZWT

Thanks for your help

0 QJ Wang over 6 years ago in reply to Giorgio Guglielmino

TI__Guru**** 197036 points

DMAREQ[31] is used for SCI TX

0 Giorgio Guglielmino over 6 years ago in reply to QJ Wang

Prodigy 235 points

Hi QJ Wang,

Thanks for your message.

Reading the Hercules Technical reference manual, it mention that the DMAREQ for SCI (LIN) are 28 and 29, where you referring to SPI?

So if i wouldn't need to chain channel 0 and 1 both for RX (to read the WCP properly) i would have Chaneel 1 available for TX (for my understanding). But using both channel 0 and 1 for RX ,leave me with no DMA channels for the TX.

Is there a workraound for this?

Thanks for your help

Giorgio

Arm-based microcontrollers

Arm-based microcontrollers forum

SCI DMA RX and TX