[U-Boot-Users] Software watchdog on mpc8247

[Mike Rapoport <mike.rapoport@gmail.com>]

On 8/25/05, Jerry Van Baren <gerald.vanbaren@smiths-aerospace.com> wrote:
>
> 
> Pointing out the obvious... looking at the disassembly, it isn't
> enabling the watchdog (SWE).  I'm guessing that you disassembled code
> where you had the watchdog disabled?

The instruction
fff031a0:       60 84 ff c3     ori     r4,r4,65479 
actually enables watchdog (65479 dec = ffc7 hex) and SWE is bit 29 of SYPCR.
 
> I see you have PBME and LBME enabled (I'm looking at an 8260 manual,
> assuming the 8247 is the same - feel free to correct me :-).  Do you
> have a 60x bus and a local bus?  Is it possible you are having an
> inadvertant bus error?  This wouldn't explain why it only happens when
> you enable the WDT, however.  Puzzling.

The 8247 does not have local bus, only 60x, but setting/clearing LBME
does not affect the operation. If I don't enable the watchdog the
system works fine.

Another thing I've noticed, most or even all 8260 based systems have
#undef CONFIG_WATCHDOG
in their config 

-- 
	Sincerely Yours,
		Mike.