I am re-posting this, since I have not got any response from anyone...
If somebody can help me solve this problem.. please...

Even if I remove my SDRAM controller completely and just keep sending
NOPs to SDRAM with A9, A10, A11 connected, the board hangs. so I think
the problem is not with the Controller code... It is somethingelse that
I might have missedout.

thanks
Mohni.

Amirtham wrote:
> Thanks for your response.
>
> I am making
>
> 1) A10 = 0 for READ and WRITE to disable AUTO-PRECHARGE since I am
> using burst transfer.
>
> 2) A10 = 1 for PRECHARGE command to precharge all the banks.
>
> Thanks!!!
>
>
> Ben Jackson wrote:
> > On 2006-12-08, Amirtham <amirtham@microview-tech.com> wrote:
> > >
> > > If I access SDRAM using address lines sdr_A8 to sdr_A0, I am able to
> > > access one row 100% correct without error. My problem starts if I
> > > connect sdr_A11, sdr_A10, sdr_A9. Board hangs.
> >
> > Do you understand the special function of A10 for READ and WRITE commands?
> > What is your address logic for read and write?
> >
> > -- 
> > Ben Jackson AD7GD
> > <ben@ben.com>
> > http://www.ben.com/

Thanks for your response.

I am making

1) A10 = 0 for READ and WRITE to disable AUTO-PRECHARGE since I am
using burst transfer.

2) A10 = 1 for PRECHARGE command to precharge all the banks.

Thanks!!!


Ben Jackson wrote:
> On 2006-12-08, Amirtham <amirtham@microview-tech.com> wrote:
> >
> > If I access SDRAM using address lines sdr_A8 to sdr_A0, I am able to
> > access one row 100% correct without error. My problem starts if I
> > connect sdr_A11, sdr_A10, sdr_A9. Board hangs.
>
> Do you understand the special function of A10 for READ and WRITE commands?
> What is your address logic for read and write?
> 
> -- 
> Ben Jackson AD7GD
> <ben@ben.com>
> http://www.ben.com/

On 2006-12-08, Amirtham <amirtham@microview-tech.com> wrote:
>
> If I access SDRAM using address lines sdr_A8 to sdr_A0, I am able to
> access one row 100% correct without error. My problem starts if I
> connect sdr_A11, sdr_A10, sdr_A9. Board hangs.

Do you understand the special function of A10 for READ and WRITE commands?
What is your address logic for read and write?

-- 
Ben Jackson AD7GD
<ben@ben.com>
http://www.ben.com/

Amirtham wrote:
> Hi Gabor,
>
> If I am not connecting A10 to SDRAM there is no problem, but if I
> connect A10 board hangs and is not even detected by the system. If
> anybody could help me get rid of this problem, please help.
>
> Thanks
> Mohni.
>
>
>
>
> Amirtham wrote:
> > "Have you tried using A9 and A11, but not A10?"
> >
> > I have only tried all A9, A10 and A11 together and not A9,A11
> > seperately.
> >
> > Thanks
> > Mohni.
> >
> > >
> > > The one thing that comes to mind is that A10 has more than one
> > > function.
> > > So if you are not generating the "AutoPrecharge" function properly
> > > during
> > > Read and Write cycles, or "SelectAllBanks" function during refresh, you
> > > can run into problems.  Have you tried using A9 and A11, but not A10?
> > > 
> > > HTH,
> > > Gabor

Hi Gabor,

If I am not connecting A10 to SDRAM there is no problem, but if I
connect A10 board hangs and is not even detected by the system. If
anybody could help me get rid of this problem, please help.

Thanks
Mohni.




Amirtham wrote:
> "Have you tried using A9 and A11, but not A10?"
>
> I have only tried all A9, A10 and A11 together and not A9,A11
> seperately.
>
> Thanks
> Mohni.
>
> >
> > The one thing that comes to mind is that A10 has more than one
> > function.
> > So if you are not generating the "AutoPrecharge" function properly
> > during
> > Read and Write cycles, or "SelectAllBanks" function during refresh, you
> > can run into problems.  Have you tried using A9 and A11, but not A10?
> > 
> > HTH,
> > Gabor

"Have you tried using A9 and A11, but not A10?"

I have only tried all A9, A10 and A11 together and not A9,A11
seperately.

Thanks
Mohni.

>
> The one thing that comes to mind is that A10 has more than one
> function.
> So if you are not generating the "AutoPrecharge" function properly
> during
> Read and Write cycles, or "SelectAllBanks" function during refresh, you
> can run into problems.  Have you tried using A9 and A11, but not A10?
> 
> HTH,
> Gabor

Amirtham wrote:
> Hi
> I have done a SDRAM controller design in spartan. using Micron
> SDRAM(128Mx32 with 4 banks).
>
> If I access SDRAM using address lines sdr_A8 to sdr_A0, I am able to
> access one row 100% correct without error. My problem starts if I
> connect sdr_A11, sdr_A10, sdr_A9. Board hangs. I am not able to detect
> the board. Some how I used a tristate buffer for sdr_A10 (which is not
> the way to do so, but still I just gave a try)  to precharge the rows,
> obviously I am not reading correct data from few rows since I have not
> connected sdr_A11 and sdr_A9. Using tirstate buffers for these llines
> also didn't help.
> I couln't trace where the problem could be. If anyone came accross such
> problem anywhere in your design experience (not neccessarily in SDRAM)
> Please help me.
>
> Thanks
> Mohni.

The one thing that comes to mind is that A10 has more than one
function.
So if you are not generating the "AutoPrecharge" function properly
during
Read and Write cycles, or "SelectAllBanks" function during refresh, you
can run into problems.  Have you tried using A9 and A11, but not A10?

HTH,
Gabor

Hi
I have done a SDRAM controller design in spartan. using Micron
SDRAM(128Mx32 with 4 banks).

If I access SDRAM using address lines sdr_A8 to sdr_A0, I am able to
access one row 100% correct without error. My problem starts if I
connect sdr_A11, sdr_A10, sdr_A9. Board hangs. I am not able to detect
the board. Some how I used a tristate buffer for sdr_A10 (which is not
the way to do so, but still I just gave a try)  to precharge the rows,
obviously I am not reading correct data from few rows since I have not
connected sdr_A11 and sdr_A9. Using tirstate buffers for these llines
also didn't help.
I couln't trace where the problem could be. If anyone came accross such
problem anywhere in your design experience (not neccessarily in SDRAM)
Please help me.

Thanks
Mohni.