Compiler to FPSLIC

Hi everyone,

I'm considering making a compiler for Atmels FPSLIC (combined 
microcontroller with FPGA). The idea is to mark expensive funktions, so
they can be implemented in the FPGA instead of normal machine code. I 
have experience with microcontrollers and construction of compilers, but 
I have only made very small test-projects with a very old FPGA and 
really buggy software.

Is this possible to make such a compiler?
Does it make sense at all to compile high-level language to a FPGA in 
this way?
Has someone else made it/is this normal procedure today ?

Regards,
Niels Sandmann

Niels Sandmann wrote:


> I'm considering making a compiler for Atmels FPSLIC (combined 
> microcontroller with FPGA). The idea is to mark expensive funktions, so
> they can be implemented in the FPGA instead of normal machine code.

Remember, that transferring operators to special purpose computing 
blocks takes some time. The gain of speed with the function block must 
be big enough to make it worth.


> I 
> have experience with microcontrollers and construction of compilers, but 
> I have only made very small test-projects with a very old FPGA and 
> really buggy software.
> 
> Is this possible to make such a compiler?
> Does it make sense at all to compile high-level language to a FPGA in 
> this way?

It is possible - if also usable, I don't know.

There is some research about Field Programmable Function Arrays. There 
compiler are used to analyze C code and map this to configurable 
function blocks in the FPFA.

Why FPFAs and not normal FPGAs? Its easier to map a software algorithm 
to a known block of hardware, where only "little" configuration is 
possible (add or sub or none, multiply or not, intermediate register 
storage or not...).

Mapping a software algorithm to FPGAs is possible with languages like 
SystemC.


I am not an expert in this area. I just want to give you some words, 
where your search may start.

Ralf

I'm curious: why have you chosen Atmel's FPSLIC?

  - a


Niels Sandmann <usenet.s@ndmann.dk> writes:
> Hi everyone,
>
> I'm considering making a compiler for Atmels FPSLIC (combined
> microcontroller with FPGA). The idea is to mark expensive funktions, so
> they can be implemented in the FPGA instead of normal machine code. I
> have experience with microcontrollers and construction of compilers,
> but I have only made very small test-projects with a very old FPGA and
> really buggy software.
>
> Is this possible to make such a compiler?
> Does it make sense at all to compile high-level language to a FPGA in
> this way?
> Has someone else made it/is this normal procedure today ?
>
> Regards,
> Niels Sandmann

-- 
PGP/GPG: 5C9F F366 C9CF 2145 E770  B1B8 EFB1 462D A146 C380

Niels Sandmann wrote:

> Is this possible to make such a compiler?

There's one for nios:
http://www.altera.com/literature/wp/C2H_Compiler_FAQ.pdf

       -- Mike Treseler

Niels Sandmann wrote:
> Hi everyone,
> 
> I'm considering making a compiler for Atmels FPSLIC (combined 
> microcontroller with FPGA). The idea is to mark expensive funktions, so
> they can be implemented in the FPGA instead of normal machine code. I 
> have experience with microcontrollers and construction of compilers, but 
> I have only made very small test-projects with a very old FPGA and 
> really buggy software.
> 
> Is this possible to make such a compiler?
> Does it make sense at all to compile high-level language to a FPGA in 
> this way?
> Has someone else made it/is this normal procedure today ?
> 
> Regards,
> Niels Sandmann

Boy, that would be interesting.  There may be part of a doctorate in 
there if you work it right.

I think this is possible.  I think the shortest road to success in the 
confines of one file would be to make a preprocessor that would extract 
the FPGA stuff to a C language design file which would then go to one of 
those nifty new C language synthesis tools.

I suspect, though, that this would cause problems with concurrency. 
Either you would have concurrency problems in the function call, or in 
making the processor wait on the FPGA and visa versa.  If you _really_ 
wanted to do this in one language you could investigate the possibility 
of reviving Occam*.

All in all, however, I think the best thing to do is find a good way 
that you can treat what the FPGA does as a concurrent process within C 
or C++.  This would mean finding a way, within C, of 'telling' the 
compiler to write something to the FPGA and kick off a computation, then 
'telling' the compiler to retrieve it, but leaving it to the software 
and FPGA designers to actually synchronize the FPGA with the processor.

* Search for 'transputer'.  The best quote I heard about Occam was 
"Oakum (Occam) is something you use to keep boats from leaking -- not a 
computer language".

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google?  See http://cfaj.freeshell.org/google/

Niels Sandmann wrote:
> Hi everyone,
> 
> I'm considering making a compiler for Atmels FPSLIC (combined 
> microcontroller with FPGA). The idea is to mark expensive funktions, so
> they can be implemented in the FPGA instead of normal machine code. 

Sometimes an 'expensive' item might be an operator.
ie Maths libraries, and their support is one productive area that
does not need armloads of new software.

 > I have experience with microcontrollers and construction of 
compilers, but
> I have only made very small test-projects with a very old FPGA and 
> really buggy software.
> 
> Is this possible to make such a compiler?

almost anything is possible ...

> Does it make sense at all to compile high-level language to a FPGA in 
> this way?

depends a lot on the FPGA, and the project, ( and the designer..)
  [ It is also a dangerous tool in the wrong hands....]

> Has someone else made it/is this normal procedure today ?

Someone has mentioned Altera's new C flow ( not cheap )


For good examples of FPGA centric work on other languages, look at

http://www.jopdesign.com/

http://myhdl.jandecaluwe.com/doku.php/cookbook:intro


and for an example of a smaller FPGA-Core, and what can be done
in core-extension, look at this carefully before commiting to the
FpSLIC ( which is rather a dead-end pathway ).

http://bleyer.org/pacoblaze/

A google on Python AVR ( if you MUST use the FpSLIC )
finds quite a lot, including

http://savannah.nongnu.org/patch/?func=detailitem&item_id=3763

http://www.ecs.soton.ac.uk/~jb1403/projects/avrpy/


-jg

Adam Megacz wrote:
> I'm curious: why have you chosen Atmel's FPSLIC?
Because I thought the integration af af Microncontroller and FPGA would 
be handy, and ease communication between the program and the FPGA.

I have prior experience with microcontrollers with Atmels AVR-core, and 
I have been pleased with them. Also, they are reasonable cheap.

Regards,
Niels Sandmann

Ralf Hildebrandt wrote:
> Remember, that transferring operators to special purpose computing 
> blocks takes some time. The gain of speed with the function block must 
> be big enough to make it worth.
Of course. It would be necessary with a good profiler.

> Mapping a software algorithm to FPGAs is possible with languages like 
> SystemC.
That sounds interesting. At first sight it seems to target simulation of 
system more than actual implementation, but I might be wrong.

> I am not an expert in this area. I just want to give you some words, 
> where your search may start.
I'm glad for any input and ideas I can get.

Regards
Niels Sandmann

Jim Granville wrote:

> depends a lot on the FPGA, and the project, ( and the designer..)
>  [ It is also a dangerous tool in the wrong hands....]
why ?

> Someone has mentioned Altera's new C flow ( not cheap )

> 
> 
> For good examples of FPGA centric work on other languages, look at
> 
> http://www.jopdesign.com/
> 
> http://myhdl.jandecaluwe.com/doku.php/cookbook:intro
> 
> 
> and for an example of a smaller FPGA-Core, and what can be done
> in core-extension, look at this carefully before commiting to the
> FpSLIC ( which is rather a dead-end pathway ).
> 
> http://bleyer.org/pacoblaze/
> 
> A google on Python AVR ( if you MUST use the FpSLIC )
> finds quite a lot, including
> 
> http://savannah.nongnu.org/patch/?func=detailitem&item_id=3763
> 
> http://www.ecs.soton.ac.uk/~jb1403/projects/avrpy/
> 
> 
> -jg
> 
> 

Jim Granville wrote:
> Niels Sandmann wrote:
>> Hi everyone,
>>
>> I'm considering making a compiler for Atmels FPSLIC (combined 
>> microcontroller with FPGA). The idea is to mark expensive funktions, so
>> they can be implemented in the FPGA instead of normal machine code. 
> 
> Sometimes an 'expensive' item might be an operator.
> ie Maths libraries, and their support is one productive area that
> does not need armloads of new software.
> 
>  > I have experience with microcontrollers and construction of 
> compilers, but
>> I have only made very small test-projects with a very old FPGA and 
>> really buggy software.
>>
>> Is this possible to make such a compiler?
> 
> almost anything is possible ...
> 
>> Does it make sense at all to compile high-level language to a FPGA in 
>> this way?
> 
> depends a lot on the FPGA, and the project, ( and the designer..)
>  [ It is also a dangerous tool in the wrong hands....]
why ?

>> Has someone else made it/is this normal procedure today ?
> 
> Someone has mentioned Altera's new C flow ( not cheap )
Do you mean their C2H-compiler for the Nios II as Mike Teseler mentioned 
in another post ?

> For good examples of FPGA centric work on other languages, look at
<snip links>
They are interesting but not exactly what I'm looking for.

> and for an example of a smaller FPGA-Core, and what can be done
> in core-extension, look at this carefully before commiting to the
> FpSLIC ( which is rather a dead-end pathway ).
I'm not committed to the FpSLIC in any way. It was just chosen due to my 
prior experience with AVR.