why:memory read/write fine, but debugger halts

Started by John Black June 14, 2004
Hi,
   I have a powerpc embedded system, in it there is a sdram chip on the
bus, if I run memory test on the sdram and the test program is loaded
from powerpc cache, the test passes. But if I use the debugger through
JTAG for powerpc to load the program into sdram, the debugger just halts
there.
    Without going into the details, could you think of any reason for
this? I am sure the debugger is fine...
    What memory test program does is read/write, what debugger does is
also read/write, seems there are some subtle difference between the two
way, but can not figure out.
   Any light?

John Black wrote:

> I have a powerpc embedded system, in it there is a sdram chip on the > bus, if I run memory test on the sdram and the test program is loaded > from powerpc cache, the test passes. But if I use the debugger through > JTAG for powerpc to load the program into sdram, the debugger just halts > there.
Simple question first: Are you trying to test the memory that your test program is running from? If so, it won't work unless you put in special provisions. Also, does your test code use the memory being tested for variables, or does the debugger use that memory? Assuming that's not the problem, use you debugger to debug the problem. ;-) Find our where/when it crashes. You will probably have to do restarts when you place the breakpoint beyond the crash point. Thad
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