15 Jun
2013
15 Jun
'13
7:59 p.m.
On Jun 15, 2013, at 10:46 PM, "Cory Smelosky" <b4 at gewt.net> wrote:
On Sat, 15 Jun 2013, Dave McGuire wrote:
Well I don't know if it's in the spec or not, but IMO if it is, it shouldn't
be. What protocol a controller implements has no bearing on how it interfaces to the
host.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
On 06/15/2013 02:29 AM, Cory Smelosky wrote:
Ahhh. Okay. I had a feeling I might've been wrong there. I couldn't recall if
the USB spec mentioned DMA or not...guess either it did or controllers added it anyway
However...it's too low-current and low-speed
for some stuff (at least in
USB 2.0). There's also no DMA...is there? (I could be wrong)
The interface has nothing to do with how (or if) its controller
accesses memory. There's nothing about USB that inherently disqualifies
it from the use of DMA, and in fact, all USB controllers I'm aware of do
in fact use DMA.