On 12/7/15 6:52 AM, Oliver Lehmann wrote:
I don't have much to offer, but I have done PIO IDE accesses on lots of
cpu's, including small ARM cpu's. I would put the code into a "read
loop" and "write loop" and look at the signals with a scope. Make sure
they look good - i.e. clean edges and the width of the assertion is
"ok". I think the minimum is something like 300ns (I may be wrong,
that's what I remember). And make sure the address is stable before
you assert WE# - I'd check that with a scope as well. If you don't have
a scope a simple logic analyser will work, but a scope is better.
I seem to recall some drives got unhappy if some of the signals on the
IDE interface were not exactly right - several need to be grounded and
several pulled up with a resistor. You don't mention what your physical
interface is. If you do I can dig up my notes and tell you what I've
done in the past (not that it's authoritative, but it's something to
compare with).
I'm sure you'll figure it out - just keep trying :-)
-brad
