The IOUSBFamily architecture is the same (save the byte-order
problem), however the controller used may be different. All of
Apple's PowerPC-based Macintosh used USB OHCI controllers for low/
full-speed, and USB EHCI controllers for hi-speed. The Intel-based
Macs have the USB UHCI controller, along with a different EHCI
controller.
Now it is possible to use PCI expansion cards to put UHCI on PowerPC,
and OHCI in an Intel machine, so that might be useful in your
debugging exercise.
In general, UHCI controllers have more constraints than the OHCI
controllers. One of the most common problems is that Isoch
transactions must not cross non-contiguous page boundaries. For
most driver developers this means they would need to make sure the
buffer used for the Isoch frame-list data is allocated as contiguous
memory.
Perhaps you can supply more details about what your application is,
and where it seems to go wrong.
David Ferguson
Apple
On Dec 27, 2007, at 8:09 AM, Lilir Chavez wrote:
Hi, list!
Could anybody tell me what is the difference between PPC & i386's usb
architecture?
My application has a connectivity module that connects the application
with usb devices. It works ok on PPC. But now, we have to support i386
and the connectivity module doesn't work properly. Sometimes the
connection is established but others no! :(
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References:
>PPC vs. i386 (From: "Lilir Chavez" <email@hidden>)
