uDMAChannelAssign()

siauhwa ong

Expert 1510 points

Hi,

What's the difference between uDMAChannelAssign() and uDMAChannelControlSet ?

I think there is an overlapping between those two API ..?

Thank you

over 10 years ago

0 Amit Ashara over 10 years ago

TI__Guru**** 244400 points

Hello Siauhwa

The uDMAChannelAssign maps the DMA Request from multiple peripherals to one of 32 channels for the uDMA.
The uDMAChannelControlSet sets the property for the channel in the control word of the channel entry

Regards
Amit

0 siauhwa ong over 10 years ago in reply to Amit Ashara

Expert 1510 points

Hi Amit,
Is uDMAChannelAssign optional, when I use the dma for the default assignment as on the table on datasheet?
For example, if I want to use UART0TX on channel 9 of dma, then I don't need to use uDMAChannelAssign , I just need :
ROM_uDMAChannelControlSet(UDMA_CHANNEL_UART0TX | UDMA_PRI_SELECT,
UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE |
UDMA_ARB_4)

thank you

0 Luis Afonso over 10 years ago in reply to siauhwa ong

Guru 20670 points

Hi siauhwa ong,

Try checking this out about more info on the DMA
sites.google.com/.../tiva-dma

uDMAChannelAssign is optional yes. There's a default channel mapping. If you use the alternative channel you also won't need to use uDMAChannelAssign.
So you are correct, for channel 9 you don't need to use the assign function since the default primary is for UART0TX

0 siauhwa ong over 10 years ago in reply to Luis Afonso

Expert 1510 points

Hi Luis,

In fact, my question was triggered from reading your website :)
But, thank you any way for the confirmation.
Have a nice day !

0 Luis Afonso over 10 years ago in reply to siauhwa ong

Guru 20670 points

Hi siauhwa,

Then I will have to remember to add a side note about just that. Feedback is always good to improve the info. Thank you!
A good day to you too.

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uDMAChannelAssign()