That’s again question where you would like to compare some general term with our implementation.
Quoting Wikipedia:
“Direct memory access (DMA) is a feature of computerized systems that allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU).”
Our implementation used on MPC55xx/56xx/57xx is called eDMA. In my opinion it is quite simple to understand the module from our reference manual. However some documents exist that could help you, for instance:
http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4522.pdf
http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4765.pdf
You may see my example showing typical use in connection to eQADC module, where eDMA is being used for eQADC command filling and result draining:
https://community.freescale.com/docs/DOC-105723
https://community.freescale.com/docs/DOC-105724
