What documentation did you use to learn how to configure the DMA in each microcontroller, the Reference Manual, Source Code examples ...?
My only current good documentation is the book MASTERING STM32 for the STM32, for the Kinetis I only have some Teensy sources, and for Atmel SAM S70 I can not find anything.
While instructional books and tutorials are extremely useful in learning, they are not any kind of documentation. While you
can work with the product documentation alone, you
cannot work with the tutorials/books alone.
In fact, I have found that the actual documentation is often all I need. Not saying you shouldn't read books and tutorials as well, but I'm very surprised you have managed to do anything without even looking at the official manufacturer documentation.
The documentation in most modern ARM microcontroller often consists of this combination of documents:
- The datasheet
- The reference manual - this basically explains almost everything. You don't have to read everything, it's a long document. You want to use DMA - read the DMA section.
- Sometimes other documents, such as programming manual, flash programming manual, application notes, etc...
- Errata sheet. Glimpse through it to see if there is something that affects you.
- Manual for the ARM core itself - not needed too often, since the compiler can handle most of the things for you transparently. I looked at it the first time only after many years of fairly complex projects!
You download these documents from your particular chip's home page. (For the ARM core reference manual, that'll be from the ARM's website, instead.)
Basic tutorials help you to better understand how to utilize the reference manual, for example, if you lack experience in the C syntax.
Otherwise, it's fairly simple for well-designed peripherals. Want to use ADC? Look up the ADC section, read how it works to understand their terminology (i.e., so you know what you can actually do with it, and to understand what you actually want to do, in their terms), then look the register section and write whatever configuration you need to use.
For poorly designed peripherals, you just need to stick to the reference manual even closer, and try things out for any undocumented hidden features or bugs, or things working differently from documentation. Unfortunately, MCU vendors don't tend to fix broken documentation to match actual behavior, or even update their errata. I guess a 100-page errata would be too shameful, so they just list 5-10% of errors to make it look like they are responsible by having an errata sheet.
Now, with these "poorly designed peripherals", having a tutorial
would be great. Often, they don't exist for these cases.
Sadly, many tutorials focus on doing utterly trivial basic tasks in the most difficult way imaginable. Think about bloating a simple LED blinking oneliner into 100 lines of code! Unfortunately, especially in the STM32 scene, I have seen the tendency to code by copypasting huge snippets of bloated code, utilizing the broken and unusable official libraries (which no one can write code for "by hand", so copypasting or autogeneration are the only options), instead of doing the thing just normally/traditionally (often writing one or two registers in a clear and simple way in two lines of code). When you simply follow the reference manual and don't look at the many tutorials, you avoid this issue completely.
But, the DMA should be fairly simple and unsurprising.
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