Dear all,

I am working on a DDR controller that stores captured video frames
from which a VGA controller retrieves data. It (DDR controller) works
fine for the first few frames but seems dead afterward. I wonder if
anyone experienced similar problem. What I did (for initial testing
purpose) is to capture and store a frame into the DDR then retrieve
the same frame (a 640x480 pixels area) over and over again.

Comments?

-M

On 21 May 2007 20:49:02 -0700, Digital Mike
<m...@gmail.com>
wrote:

>Dear all,
>
>I am working on a DDR controller that stores captured video frames
>from which a VGA controller retrieves data. It (DDR controller) works
>fine for the first few frames but seems dead afterward. I wonder if
>anyone experienced similar problem. What I did (for initial testing
>purpose) is to capture and store a frame into the DDR then retrieve
>the same frame (a 640x480 pixels area) over and over again.
>

I don't really know how DDR manages refreshing, have you taken care of
it?

Zara

On 22 May, 03:49, Digital Mike
<michaelmk...@gmail.com> wrote:
> Dear all,
>
> I am working on a DDR controller that stores captured video frames
> from which a VGA controller retrieves data. It (DDR controller) works
> fine for the first few frames but seems dead afterward. I wonder if
> anyone experienced similar problem. What I did (for initial testing
> purpose) is to capture and store a frame into the DDR then retrieve
> the same frame (a 640x480 pixels area) over and over again.
>
> Comments?
>
> -M

Hi Mike,
I've got some experience with DDR2 controller.
If you send me your code I can have a look.

Francesco

On 5=A4=EB22=A4=E9, =A4U=A4=C83=AE=C943=A4=C0,
Zara <me_z...@dea.spamcon.or=
g> wrote:
> On 21 May 2007 20:49:02 -0700, Digital Mike <michaelmk...@gmail.com>
> wrote:
>
> >Dear all,
>
> >I am working on a DDR controller that stores captured video frames
> >from which a VGA controller retrieves data. It (DDR controller) works
> >fine for the first few frames but seems dead afterward. I wonder if
> >anyone experienced similar problem. What I did (for initial testing
> >purpose) is to capture and store a frame into the DDR then retrieve
> >the same frame (a 640x480 pixels area) over and over again.
>
> I don't really know how DDR manages refreshing, have you taken care of
> it?
>
> Zara

Zara,

Yes the controller is configured to auto-refresh DDR at the required
intervals.

-M

On May 22, 2:00 pm,
francescopoder...@googlemail.com wrote:
> On 22 May, 03:49, Digital Mike <michaelmk...@gmail.com> wrote:
>
> > Dear all,
>
> > I am working on a DDR controller that stores captured video frames
> > from which a VGA controller retrieves data. It (DDR controller) works
> > fine for the first few frames but seems dead afterward. I wonder if
> > anyone experienced similar problem. What I did (for initial testing
> > purpose) is to capture and store a frame into the DDR then retrieve
> > the same frame (a 640x480 pixels area) over and over again.
>
> > Comments?
>
> > -M
>
> Hi Mike,
> I've got some experience with DDR2 controller.
> If you send me your code I can have a look.
>
> Francesco

Hi
Francesco
I am currently working on DDR2 controller for BL 8.
My own code is giving good results when i  verified with memory model
from MICRON.
Now my problem is memory on the board  is not sending 4 DQS   clock
pulses. it seems to be sending for burst lenth 4.

For ur IDEA  some results  i observed

If i  won't   Initialize properly  it is not responding at all . no
DQS nothing is comming .
if i initialize it properly its giving DQS signal of two sine clock
pulses.
If i write with 101010101 .... of each location i am getting two sine
clock pulses on DQ pin while reading .
if i write with all ZERO's i am getting ZERO' on DQ pin.

so i think inialization is happenig properly. some problem persistence
still some where .
If u have any IDEA please help me regarding  this.
with regards......
sudhakar

On 22 May, 13:41, sudhakar...@gmail.com wrote:
> On May 22, 2:00 pm, francescopoder...@googlemail.com wrote:
>
>
>
> > On 22 May, 03:49, Digital Mike <michaelmk...@gmail.com> wrote:
>
> > > Dear all,
>
> > > I am working on a DDR controller that stores captured video frames
> > > from which a VGA controller retrieves data. It (DDR controller) works
> > > fine for the first few frames but seems dead afterward. I wonder if
> > > anyone experienced similar problem. What I did (for initial testing
> > > purpose) is to capture and store a frame into the DDR then retrieve
> > > the same frame (a 640x480 pixels area) over and over again.
>
> > > Comments?
>
> > > -M
>
> > Hi Mike,
> > I've got some experience with DDR2 controller.
> > If you send me your code I can have a look.
>
> > Francesco
>
> Hi
> Francesco
> I am currently working on DDR2 controller for BL 8.
> My own code is giving good results when i  verified with memory model
> from MICRON.
> Now my problem is memory on the board  is not sending 4 DQS   clock
> pulses. it seems to be sending for burst lenth 4.
>
> For ur IDEA  some results  i observed
>
> If i  won't   Initialize properly  it is not responding at all . no
> DQS nothing is comming .
> if i initialize it properly its giving DQS signal of two sine clock
> pulses.
> If i write with 101010101 .... of each location i am getting two sine
> clock pulses on DQ pin while reading .
> if i write with all ZERO's i am getting ZERO' on DQ pin.
>
> so i think inialization is happenig properly. some problem persistence
> still some where .
> If u have any IDEA please help me regarding  this.
> with regards......
> sudhakar

Hi sudhakar,
What kind of FPGA wre you using?
On the samsung website you can download some ddr2 memory model to
verify that the initialization is ok.
I don't have enought informations from you to help you.
Last time I used MIG 7.1 succesfully .
So if you are using a Xilinx FPGA I can reccomend you to use the MIG.

Francesco