[U-Boot-Users] Setting up reset on the EP885C
wd at denx.de
Tue Jul 12 22:20:50 CEST 2005
In message <loom.20050712T193709-463 at post.gmane.org> you wrote:
> However, when I try to run from 0xFC000000 or 0xFC000100 I get no display at
> all, and the BDM reads -TARGET: STOPPED. Also, when I try to just program to
> flash and then reset the board it seems as if no code is executing.
Don't try to run any code from any specific address at all. Let the
CPU do what it wants to do. Force a reset, and then just single step
in your debugger. I would be surprised if the CPU would not start at
either 0x0100 or 0xFFF0100.
> Can anyone verify that 0xFC000000 is the correct flash location for an EP885C?
It is as good as any other. You can map the flash basicly everywhere
and get a working system.
> Also, I am thinking that by resetting the hard reset configuration word, I could
Oops? I cannot parse that. Reset the HRCW? What exactly do you mean?
> force the board to jump to the correct instruction location, but I am at a loss
> to figure out how to change the hrcw's value. Any help would be greatly
The HRCW is something you (resp. your hadrware) applies to the bus at
reset. Study the schematics of your hw - this might be as simple as
pull-ups or -downs (if your hw is half-broken), or some more
sophisticated way to drive a certain value on the bus in this
situation. Unless you use some prgrammable device fort his purpose
you cannot "reset" the HRCW - and if you can change it, it will take
effect only at the next reset. It will definitely not make the CPU
"jump to the correct instruction location".
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Any sufficiently advanced technology is indistinguishable from magic.
Clarke's Third Law - _Profiles of the Future_ (1962; rev. 1973)
``Hazards of Prophecy: The Failure of Imagination''
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