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Message
From: "Damjan Lampret" <lampret@o...>
Date: Fri, 31 Oct 2003 17:39:51 +0100
Subject: Re: [openrisc] Instruction l.mfspr ouput is not expected!
John,
if you haven't initialized R5 then R5 is not initialized. In or1ksim GPRs at
reset are always zero. In RTL they might not have to be zero, they might be
X value. This is because in RTL GPR can be implemented with RAM hard macro
which in most cases can't be reset (the content of RAM). So by default the
reset vector always contains set of instructions that zero all GPRs. Lookm
at any complete software that runs on or1200. Etiehr uclinux, orpmon, eCos
etc. You just copy reset vector routine.
regards,
Damjan
----- Original Message -----
From: <John.Smith@y...>
To: <openrisc@o...>
Sent: Friday, October 31, 2003 5:22 PM
Subject: Re: [openrisc] Instruction l.mfspr ouput is not expected!
>
>
> ----- Original Message -----
> From: "Damjan Lampret" <lampret@o... >
> To: <openrisc@o... >
> Date: Fri, 31 Oct 2003 17:06:09 +0100
> Subject: Re: [openrisc] Instruction l.mfspr ouput is not expected!
> Hi
> No,I did not initialize R5.
> I have just tested the simple program with three line.
> Is there any other possible reason?
> The code is so large that I can not find where is the source of the
> error.
> Regards
> >
> >
> > > No,It is not zero I found.SR is 0x8001.I am using modelsim.
> > > It is strange that register SR is 0x8001.I monitored SR in
> > module
> > > or1200_sprs.On reset SR should be 0x8001.
> > > And in or1ksim the result is right.
> > > I don't know what is wrong yet!:(
> >
> > Could happen if we you different R5 in or1ksim and rtl simulation.
> > Where do
> > you initialize R5? Put another instructions something like
> >
> > l.addi r5,r0,0
> >
> > before the three instructions.
> >
> > regards,
> > Damjan
> >
>
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