Forums

JBits and Spartan

Started by alonzo October 6, 2004
Hello, 
Does somebody know if the last version of JBits (3.0) will work with
spartans family? I know JBits 3.0 supports Virtex II, and an older version
supported Virtex... but .. Spartan is kind of a Virtex.. so .. have anyone
try this before?

Thanks,
Alonzo.


Sadly Xilinx has abandoned JBits.

Question for Xilinx: with JBits now DOA, how are customers supposed to
use the ICAPs?  Are they now strictly intended for "swapping" a set of
prebuilt configurations?  Without something like JBits you can't
really do runtime template assembly AFAICT...

  - a


"alonzo" <rha_x@yahoo.com> writes:
> Hello, > Does somebody know if the last version of JBits (3.0) will work with > spartans family? I know JBits 3.0 supports Virtex II, and an older version > supported Virtex... but .. Spartan is kind of a Virtex.. so .. have anyone > try this before? > > Thanks, > Alonzo. >
-- I wrote my own mail server and it still has a few bugs. If you send me a message and it bounces, please forward the bounce message to megacz@gmail.com. Thanks!
Adam Megacz wrote:
> > Sadly Xilinx has abandoned JBits.
Is this true? JBits support for V2 was announced just a few months ago.
> Question for Xilinx: with JBits now DOA, how are customers supposed to > use the ICAPs? Are they now strictly intended for "swapping" a set of > prebuilt configurations? Without something like JBits you can't > really do runtime template assembly AFAICT...
Your question has a false premise - customers *aren't* supposed to use ICAP. :-S ... OK so I'm joking, but only just... ICAP is there because it helps Xilinx test chips. They make it visible in the tools etc because it has some interesting research opportunities. It's a bit of a chicken and egg problem - if someone can demonstrate a killer-app for ICAP and partial-reconfig, then support will follow. But without support, developing the killer-app is very difficult... Regards, John
John Williams wrote:
> > Adam Megacz wrote: > > > > Sadly Xilinx has abandoned JBits. > > Is this true? JBits support for V2 was announced just a few months ago. > > > Question for Xilinx: with JBits now DOA, how are customers supposed to > > use the ICAPs? Are they now strictly intended for "swapping" a set of > > prebuilt configurations? Without something like JBits you can't > > really do runtime template assembly AFAICT... > > Your question has a false premise - customers *aren't* supposed to use > ICAP. :-S ... OK so I'm joking, but only just... > > ICAP is there because it helps Xilinx test chips. They make it visible > in the tools etc because it has some interesting research opportunities. > > It's a bit of a chicken and egg problem - if someone can demonstrate a > killer-app for ICAP and partial-reconfig, then support will follow. But > without support, developing the killer-app is very difficult...
Xilinx had a lot of new tool features they were supporting such as modular configuration. I was told that they were commited to supporting the Spartan 3 devices. But that support never materialized and I dont' see where the new V4 chips are supported yet. Maybe they just don't see much need and are dropping some of these advanced tools on the newer chips. Or maybe it is the lack of tri-state buffers. I know the Spartan 3 chips have none, do the Virtex 4 chips have any internal tri-states? -- Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX
rickman wrote:
> John Williams wrote: > >>Adam Megacz wrote: >> >>>Question for Xilinx: with JBits now DOA, how are customers supposed to >>>use the ICAPs? Are they now strictly intended for "swapping" a set of >>>prebuilt configurations? Without something like JBits you can't >>>really do runtime template assembly AFAICT... >> >>Your question has a false premise - customers *aren't* supposed to use >>ICAP. :-S ... OK so I'm joking, but only just... >> >>ICAP is there because it helps Xilinx test chips. They make it visible >>in the tools etc because it has some interesting research opportunities. >> >>It's a bit of a chicken and egg problem - if someone can demonstrate a >>killer-app for ICAP and partial-reconfig, then support will follow. But >>without support, developing the killer-app is very difficult... > > Xilinx had a lot of new tool features they were supporting such as > modular configuration. I was told that they were commited to supporting > the Spartan 3 devices. But that support never materialized and I dont' > see where the new V4 chips are supported yet. Maybe they just don't see > much need and are dropping some of these advanced tools on the newer > chips.
I think the problem is probably in the underlying wire database (NCD) that the current-gen tools use. Using constraints for modular/partial flow is not ideal. Better would be to have a database that has the equivalent of the SQL "view" construct - create a virtual device that is some spatial subset of the full device, with full P&R capability over that subset. Of course I'm not saying it's easy!
> Or maybe it is the lack of tri-state buffers. I know the > Spartan 3 chips have none, do the Virtex 4 chips have any internal > tri-states?
I'm speculating again, but I think the whole tri-state/bus macro thing is a bit of a red-herring - it's just the easiest, guaranteed safe way to do it with the existing tools and tech. Think about it, on-chip bidirectional buses are all done with wired-OR these days, yet functionally it acts like a tri-stated bus. Perhaps the same could be done with partial reconfiguration, it's just too hard to force the tools to obey such a construct. The bus-macros are so inefficient - one of my students looked into making a 32-bit bus macro, it would take more than the height of a V2-1000 device! To do real work with dynamic modules etc you need wide buses - bus macros just aren't gonna cut it. Anyway that's enough speculation for tonight :) John
Does anybody know where JBits verson 1.0 or 1.1 can be downloaded.
Thanks