On 11 June 2012 15:38, Edgar E. Iglesias <edgar.igles...@gmail.com> wrote: > On Mon, Jun 11, 2012 at 02:39:56PM +0100, Peter Maydell wrote: >> Ideally the interface used by DMA controllers should be identical to >> the interface used by CPUs to talk to the rest of the system: it's >> exactly the same bus interface in hardware, after all. > > I thought we were talking about the interface between the DMA ctrl > and the I/O (devices). Not between the DMA and the "memory" bus system.
In hardware (at least for AXI) they're the same thing. A DMA controller is a bus master, just like a CPU. They don't care whether the slave is RAM or a device, they're just issuing memory transactions to addresses. -- PMM
