Stefan Roese wrote: > On Wednesday 23 April 2008, Dave Littell wrote: >> I'm working on an AMCC PPC440EPx-based platform that's similar to the >> Sequoia. The board runs pretty well, but occasionally takes exceptions >> both in U-Boot and while running Linux. The exceptions vary from >> Illegal Instructions to FP Unavailable to FP Unimplemented to ITLB and >> DTLB Errors, to DSI, etc., which made us believe there's a problem with >> SDRAM. > > Yes, this is my first idea too. Almost every time such "random" errors are > seen, SDRAM setup/initialization is the cause for it. > >> Sometimes there are simple hard lockups from which even the JTAG >> can't regain control. However, the SDRAM physical/electrical and DDR >> Controller configurations have been investigated in detail (and some >> corrections made) with no resulting improvement in the exception behavior. > > Is the SDRAM termination similar to the one used on Sequoia too? Are you > using > soldered chips and not DIMM modules? Is ECC available? >
Termination: very likely - they stayed very close to Sequoia, but I'll ask. We're using soldered chips and there's no ECC. >> We see problems primarily at 667 MHz but have noted some issues at 533 >> MHz as well. Some boards seem particularly susceptible to this while >> others rarely (if ever) exhibit the problem. >> >> At this point all possibilities are on the table and I'm looking for any >> input from anyone with experience (good, bad, or whatever) with this >> processor and/or designs similar to the Sequoia. > > If you scan the U-Boot mailing list for 440EPx/Denali DDR2 problems, you will > most likely find some references. > Will do, thanks for the pointer. > Please note that I recently introduced a CFG_MEM_TOP_HIDE option for the > 440EPx CHIP 11 errata. I suggest you take a look at this too and see if this > changes your behavior. > I remember this - PPC440EPx Revision A errata CHIP_11, right? Thanks, Dave ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ U-Boot-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/u-boot-users
