[theora-dev] Next step of Hardware Theora

Sat May 12 20:27:06 PDT 2007

I updated the wiki page:

http://wiki.xiph.org/index.php/TheoraHardware

:-)

On 5/12/07, Felipe Portavales Goldstein <portavales at gmail.com> wrote:
> On 5/11/07, Leonardo de Paula Rosa Piga <lpiga at terra.com.br> wrote:
> > On 5/11/07, André Costa <andre.lnc at gmail.com> wrote:
> > > Thanks for Feedback,
> > >
> > > I have been talked with some people, we (I, Felipe and Leonardo) know a
> > > group (that worked with us) that did a MPEG decoder in hardware at Brazil
> > > and they have been helped us with some tips in others list. Also, I had a
> > > chat with my professor and now I think it is more clear about LEON and SDRAM
> > > controller.
> > >
> > > First, I agree with you, the priority should be the LEON. How Ralph said,
> > > until this is done, no one else can play with the code.
> > >
> > > LEON3
> > > figure 1:
> > > http://www.students.ic.unicamp.br/~ra031198/leon3.JPG
> > >
> > > It is a excellent nonproprietay processor, very flexible and has a lot of
> > > components that can be pluged (like Memory controller, jTag, AMBA).
> > >
> > > The steps would be:
> > >
> > > - To find a configuration that be able to decode the Theora.
> > > - Synthesis of LEON3
> > > - To compile only de initial part of Theora for LEON and to run this inside
> > > of the LEON.
> > > - To change the handshake of Theora Hardware of AVALON to AMBA protocol.
> > > - Integrate the processor and theora hardware
> > >
> > > In think the hard part would be to debug this, construct a testbench to test
> > > this. To learn the LEON3 features/configuration and the protocols would be
> > > dificult too.
> > >
> > > SDRAM Controller and FlashCard
> > > Yes. To do it in Hardware would be much complicate, because there are many
> > > constrains and the SDRAM is very rigid with timing. For this, I would need
> > > to have a good study of the datasheet before to start the developing.
> > >
> > > In the other list we had the ideia of work with a Flash Card, but It is very
> > > slow. The Flash card would be nice to store the Videos encoded.
> > >
> > > LEON3/Memory Controller
> > >
> > > How you can see in figure 1, the LEON3 has a Memory Controller of SDRAM.
> > > The LEON will use this to execute the functions of the intial decoding.
> > > figure 2:
> > > http://www.students.ic.unicamp.br/~ra031198/fig2.JPG
> > >
> > > Ok, then we can use this SDRAM memory controller to buffer of the Theora
> > > Hardware?
> > > Something like this:
> > > figure 3:
> > > http://www.students.ic.unicamp.br/~ra031198/fig3.JPG
> >
> > I don't like the implementation above. As you said I think that it
> > might overload the AMBA bus.
>
> Me too
> I agree with Leonardo
> The AMBA bus will be overloaded and will not be able to give the
> throughput that we need.
> This choice is not feasible.
>
>
> >
> >
> > >
> > > This answer I still don't, because it's depende of the AMBA, frequecie of
> > > operation and data throuput. AMBA is a little slow, I think it will not get
> > > to answer the LEON and Theora Hardware requests in time. But It is could be
> > > tested.
> > >
> > > If it is not ok, the alternative would be copy the memory controller to use
> > > with the SRAM
> > > figure 4:
> > > http://www.students.ic.unicamp.br/~ra031198/fig4.JPG
> > >
> >
> > I think this is better because in this implementation the processor is
> > used just for the software part. And if we have throughput problem we
> > can easier convert to a pipelined implementation than the other one.
>
> I agree with Leonardo.
>
>
> >
> > >
> > > LEON3/VGA controller
> > > Beyond this, LEON3 has a VGA controller, but I don't know if it would be
> > > necessary to plug with Theora Hardware. But I think that could happen the
> > > same problem of the SDRAM, It could overload the AMBA. And then, I think It
> > > should be unpluged of AMBA and to plug directly with the Theora Hardware.
> > > The group that we know did a Video Controller (for MPEG) in hardware. It
> > > seems to be not much dificult to do, maybe it is more interesting to
> > > Leonardo to do one.
> > >
> >
> > Yes, I have studied the Lancelot VGA controller (this is the board we
> > have in our laboratory). I'm thinking in developing the VGA controller
> > as a separated module from Theora Hardware. In this manner the
> > integration will be done by a simple handshake protocol.
> > This would reduce the dependency between the VGA Controller  and the
> > Theora Hardware.
>
> This is good
> A modular design is easier to develop and maintain too.
>
> >
> > >
> > >
> > > What do you think?
> > >
> > > André Costa
> > >
> > >
> > > On 5/9/07, Timothy B. Terriberry <tterribe at vt.edu> wrote:
> > > > >> Derf, what do you think?
> > > >
> > > > I don't know enough about the complexity implementing an SDRAM
> > > > controller to say whether it should be one of the "primary goals" or a
> > > > "secondary goal, time permitting". However, I think it would be nice to
> > > > shoot for completing integration with Leon by the midterm date (the week
> > > > of July 9; in approximately two months).  Then you will have the entire
> > > > second half of the project to focus on the SDRAM controller. That may
> > > > not be enough to finish it if it is really as complex as last year's
> > > > entire GSoC project, but I would think you could make some good
> > > > progress. When you talk to your professor tomorrow, he may be able to
> > > > give you a better idea whether or not this is reasonable.
> > > >
> > >
> > >
> > >
> > > --
> > >
> > > André Costa
> > > Gerente Técnico
> > > Projeto BrazilIP
> > > LSC IC-UNICAMP
> > >
> > > Cel: + 55 13 9201 1870
> > > http://www.brazilip.org.br/
> >
> >
> > --
> > Leonardo de Paula Rosa Piga
> > Undergraduate Computer Engineering Student
> > LSC - IC - UNICAMP
> > http://www.students.ic.unicamp.br/~ra033956
> >
>
>
> --
> ________________________________________
> Felipe Portavales Goldstein <portavales at gmail>
> Undergraduate Student - IC-UNICAMP
> Computer Systems Laboratory
> http://www.students.ic.unicamp.br/~ra023772/
>

-- 
________________________________________
Felipe Portavales Goldstein <portavales at gmail>
Undergraduate Student - IC-UNICAMP
Computer Systems Laboratory
http://www.students.ic.unicamp.br/~ra023772/