Processor Expert Software中的主题 What is the difference between DMA_LDD and DMATransfer_LDD?

What is the difference between DMA_LDD and DMATransfer_LDD?

jackblather — Mon, 28 Jul 2014 21:52:12 GMT

I am trying to set up SPI as a master using DMA. Which once should I use, DMA_LDD or DMATransfer_LDD? I have an external device sending a block of data. That device does not send data until I send an initiating command (SPI or GPIO).

I have PEx v10.2 with update.

I also see that starting with PEx v10.3 there is a new LDD Component, "DMAChannel_LDD". What functionality does that new device provide over DMA_LDD and DMATransfer_LDD? This is not mentioned in the release notes.

Re: What is the difference between DMA_LDD and DMATransfer_LDD?

Rick_Li — Tue, 29 Jul 2014 05:36:10 GMT

HI Jack,

please use DMATransfer_LDD for your application.

the component DMATransfer_LDD provides DMA transfer configuration functionality. while component DMA_LDD provides internal direct memory access controller peripheral functionality.

component DMATransfer_LDD can't access DMA on-chip peripheral directly but it is using DMA_LDD as interface.

DMATransfer_LDD component allows user to have predefined set of particular DMA transfers.

for details of these two components, I would suggest reading help information. it can be access by just right click the component and then click "Help on Componet".

hope it helps!

Re: What is the difference between DMA_LDD and DMATransfer_LDD?

jackblather — Tue, 29 Jul 2014 16:26:02 GMT

Thanks!

I also found a bunch of PDF help guides for each PEx component in ~/.ds-5/workbench/ProcessorExpert/Help/ComponentUserGuides

Re: What is the difference between DMA_LDD and DMATransfer_LDD?

MVa — Wed, 30 Jul 2014 06:03:23 GMT

Hi Jack,

in CodeWarrior 10.5 and higher these DMA_LDD and DMATransfer_LDD were replaced by new DMA and DMAChannel_LDD components. These new components provides unified interface for both DMA (e.g. Kinetis L family) and eDMA (e.g. Kinetis K family) peripherals available on Kinetis MCUs and require less memory resources. See DMAChannel_LDD documentation for more details.

Please note that old DMA_LDD and DMATransfer_LDD are not supported for new MCUs and are provided for backward compatibility only. These old components should not be used for new designes.

Best Regards

Marek Varecha

Processor Expert Team