Is DMA Double Buffer Mode only Peripheral to Memory?

[Mike Hooper]

Posted on July 28, 2017 at 14:40

It appears from the (rather lacking) documentation that the DMA Double Buffer Mode is only a Peripheral to Memory transaction. Is this correct? Or can I use double buffering from memory to peripheral?

[Tesla DeLorean]

Posted on July 28, 2017 at 15:07

On what part?

I'd assume the implementation will be highly symmetrical. The mechanics are there to ping-pong between two buffers whether the transfer is to or from is a separate and independent step in the sequence.

Not single memory to multiple peripherals.

[Amel NASRI]

Posted on July 28, 2017 at 19:01

Hi

Hooper.Mike

‌,

In

http://www.st.com/content/ccc/resource/technical/document/application_note/27/46/7c/ea/2d/91/40/a9/DM00046pdf/files/DM00046pdf/jcr:content/translations/en.DM00046pdf

we say 'A double-buffer stream works as a regular (single-buffer) stream, with the difference that it has two memory pointers. '

So both directions can be used.

-Amel

[waclawek.jan · Accepted solution]

Posted on July 29, 2017 at 10:13

Please specify, which part are you using.

AFAIK, the single-port DMA (F1/F0/L1/L4/L0) does not feature double-buffer mode.

I am trying to find a RM with the 'F2/'F4/'F7-style double/triple-port DMA, where textual search for ''double'' would not stumble upon several mentions of both direction being available, including the following table:

JW

PS. Amel, RM0090 of 'F0xx, RM0360 of 'F030 and possibly others contain a mention of ''double buffer mode'' in the ADC chapter, which probably ought to be removed.

[Amel NASRI]

Posted on July 30, 2017 at 01:16

Ok

Waclawek.Jan

‌, I'll take care to check this.

-Amel

[Mike Hooper]

Posted on July 31, 2017 at 13:10

Thanks all. I did eventually find the above mentioned table in the RM and will be giving it a try this week.