> Hi all, > I'm thinking about a new board for JOP (or MB, NIOS). The board should be > small and > cheap (below the S3 Starter Kit). It should only contain the absolute > necessary parts for a > CPU design. Here is the suggested part list: > > What do you guys think about this idea? Does it make sense to build a > another FPGA board?Martin, If you do decide to build a new proto board make sure you've got some form of securely mounting it. If you go with a SimmStick this is taken care of, but I had problems mounting your Cyclone JOP boards for prototyping. I didn't have time to design/build a motherboard to plug the modules into to get access to the connectors so had to build a complicated jig to hold them securely. Nial. ------------------------------------------------------------- Nial Stewart Developments Ltd FPGA and High Speed Digital Design www.nialstewartdevelopments.co.uk
SimmStick FPGA module
Started by ●February 8, 2005
Reply by ●February 8, 20052005-02-08
Reply by ●February 8, 20052005-02-08
Antti Lukats wrote:> "Laurent Gauch" <laurent.gauch@DELETEALLCAPSamontec.com> schrieb im > Newsbeitrag news:4208CF2C.6010504@DELETEALLCAPSamontec.com... > >>Kolja Sulimma wrote: >> >>>Martin Schoeberl wrote: > > >>What is the use of the finger connector on Micromodule >> >>Larry > > HAHA its duplicate of your favorite interface JTAG! > Need to get piece of old floppy connector and saw it in pieces! > > Antti > >thanks Antti !
Reply by ●February 8, 20052005-02-08
Kolja,>> CPU design. Here is the suggested part list: >> >> FPGA: Cyclone EP1C3 or Spartan XC3S200 >> 256Kx16 15ns SRAM >> 2 MBit serial Flash >> 3.3V linear regulation >> switching regulator for the core voltage >> 20MHz clock to the PLL input > [..] >> What do you guys think about this idea? Does it make sense to build a another FPGA board? > > What you describe is essentially our Micromodule minus USB plus SRAM. > http://www.trenz-electronic.de/prod/proden18.htm > > If you can live with our form factor we could collaborate on a version with sram instead of usb. >I think the Micromodule is a very nice design in it's version as it is (with USB). If you only add SRAM you still need a base board.> For a cluster you can build a stack of these boards.Stacking is a nice idea. I also thought about stacking my Cyclone modules when I've too many of them laying around ;-)> > However I doubt that it makes sense to have boards that are so similar. >I think I will go with a Cyclone. So our two boards are not so similar. Martin
Reply by ●February 8, 20052005-02-08
>> However, SRAM is way much simpler to handle. I think SDRAM is a pain. > > SDRAM is not that hard and having a lot more capacity is a big plus IMHO, that > worth the extra work.Yes, I will go with the SDRAM. Do you have an idea what chips are used these days. I've found Micron MT48LC4M16A2 could be a choice.>> The 3.3V linear regulation is only for the IO. The core voltage gets a switching >> regulator. If you are using this module in a 3.3V SimmStick bus you can go >> without the linear regulation on board (will be a sloder jumper) > > Have a look at > http://focus.ti.com/lit/ds/symlink/tps75003.pdf > > Really nice little chip ;)Nice, but still many external components. However, as it looks like that I will use the Cyclone I only need one switched power supply (1.5V).>>>> 20MHz clock to the PLL input > > If there is a spare centimeter square, adding an unpopulated space for another > XTAL maybe.Why? You can use the internal PLL. And I'm not using an XTAL, but an integrated osci. If you really need a different frequency than you can change the osci yourself.> Other remarks : Having a few I/Os routed as differential pair to the connector could be niceDo you mean LVDS standard with the termination resistor network? Martin
Reply by ●February 8, 20052005-02-08
> Martin, > > If you do decide to build a new proto board make sure you've got some form of > securely mounting it. If you go with a SimmStick this is taken care of, but I > had problems mounting your Cyclone JOP boards for prototyping. I didn't > have time to design/build a motherboard to plug the modules into to get access > to the connectors so had to build a complicated jig to hold them securely.He he. You do not need a real motherboard. Just single row connectors on a breadboard and go (or the expensive version of this that I provide: Simpexp) Martin
Reply by ●February 8, 20052005-02-08
Martin Schoeberl wrote:>>>However, SRAM is way much simpler to handle. I think SDRAM is a pain. >> >>SDRAM is not that hard and having a lot more capacity is a big plus IMHO, that >>worth the extra work. > > > Yes, I will go with the SDRAM. Do you have an idea what chips are used these days. > I've found Micron MT48LC4M16A2 could be a choice.Yes, looks good to me. If you still have spare IO, routing the address lines for the superior model might be interesting. Maybe there is no more line to route actually, I didn't check> However, as it looks like that I will use > the Cyclone I only need one switched power supply (1.5V).May I ask why ? The EP1C3 has 2910 L.E., 1 PLL and 60kbits of ram. The XC3S200 has 4320 L.C., 4 DCM/DLL, 216kbits of ram and 12 dedicated multipliers (Note that it's _not_ a A vs X issue ! Theses chips are just not of the same generation ...)>>>>> 20MHz clock to the PLL input >> >>If there is a spare centimeter square, adding an unpopulated space for another >>XTAL maybe. > > Why? You can use the internal PLL. And I'm not using an XTAL, but an integrated osci. > If you really need a different frequency than you can change the osci yourself.First yes sorry I always write XTAL while I mean a complete osc ... ;) Why : It's not big and when you have a specific frequency for a screen / uart / ... generating it with the PLL is sometimes annoying ...>>Other remarks : Having a few I/Os routed as differential pair to the connector could be nice > > Do you mean LVDS standard with the termination resistor network?Yes, that what I meant. Don't put the resitors by default, just route them as if they were differential. Sylvain
Reply by ●February 8, 20052005-02-08
> Hi all, > > I'm thinking about a new board for JOP (or MB, NIOS). The board should be > small and > cheap (below the S3 Starter Kit). It should only contain the absolute > necessary parts for a > CPU design. Here is the suggested part list: > > FPGA: Cyclone EP1C3 or Spartan XC3S200 > 256Kx16 15ns SRAM > 2 MBit serial Flash > 3.3V linear regulation > switching regulator for the core voltage > 20MHz clock to the PLL input > > I've not yet decided about a X or A device. > > A remaining question is about the form factor. I still think it makes > sense to build > the board as a module that can be integrated in a board with the > peripherals (similar > to the ACEX and Cyclone modules I've done). There are two 'standards' > available: > > 1.) SimmStick, where the boards are designed as the 'old' PC SIMMs (see > [1]). > > 2.) The 'Basic Stamp' design is a board in the form of an old 40-pin (or > less) DIL IC. > An example (from a Java processor competitor): [2] > > For a Java solution in an FPGA this board should beat the Systronix aJ100 > Java processor > modules (JStamp or JStick [3] - they have both form factors) in > performance and price. > One nice thing about the SimmStick is that there are plenty of I/O boards > already available > (see [4, 5, 6]). > It seems a relative 'old' design, but it's a bus and I can build my first > JOP cluster with those > boards ;-) > > What do you guys think about this idea? Does it make sense to build a > another FPGA board? > > [1] http://www.simmstick.com/ > [2] http://jstamp.systronix.com/jstamp_photos.htm > [3] http://www.jstik.com/ > [4] http://www.dontronics.com/dt.html > [5] http://www.hobbyengineering.com/SectionSS.html > [6] http://www.simmstick.com/simmstic1.htm > > Martin > ---------------------------------------------- > JOP - a Java Processor core for FPGAs: > http://www.jopdesign.com/ >I personally thought that the simmstick standard has way too few pins (30) for any serious work. That was the main reason for me to 'invent :-)' my own bus standard. The latest incarnation is called 'H-Storm' and can be found here: http://h-storm.tantos.homedns.org. I would suggest you to take a look. It has more pins (72) and thus much more versatile than the simmstick. It's already 3.3V powered so you can save the regulator. Even better: it has pins for 2.5 and 1.8V power as well, so you might not need to deal with power at all (not with the SpartanIII, the core power there is 1.2V). I'm in the process of building an FPGA board to that bus myself, using a spartan II-e device, but it shure would be nice to see someone else building something along those lines. Regards, Andras Tantos
Reply by ●February 9, 20052005-02-09
>> Yes, I will go with the SDRAM. Do you have an idea what chips are used these days. >> I've found Micron MT48LC4M16A2 could be a choice. > > Yes, looks good to me. If you still have spare IO, routing the address lines for > the superior model might be interesting. Maybe there is no more line to route actually, > I didn't checkIt's almost the same pinout for up to 64MByte (only one additional address line).>> However, as it looks like that I will use >> the Cyclone I only need one switched power supply (1.5V). > > May I ask why ? > > The EP1C3 has 2910 L.E., 1 PLL and 60kbits of ram. > The XC3S200 has 4320 L.C., 4 DCM/DLL, 216kbits of ram and 12 dedicated multipliers >A little correction: The Spartan-3 has 3,840 LC/Es (multiply the Slices by two and you get the LUT count). Yes you're right, S3-200 is larger, has more memory (but less memory blocks 12 vs. 13) and multipliers. However, my main application for this board, JOP, can be clocked higher in the Cyclone than in the Spartan-3 (101MHz vs 83MHz, both fastest speed grades). The S3-200 is more expensive than the EP1C3. However, both are large enough for a CPU with some peripherals. That's the main application, in my opinion, for this board. And another reason: There are many Xilinx boards (and also cheap one) available, but not so many for Cyclones. This board would be very similar to Koljas Micromodule.>>>If there is a spare centimeter square, adding an unpopulated space for another >>>XTAL maybe. >> Why? You can use the internal PLL. And I'm not using an XTAL, but an integrated osci. >> If you really need a different frequency than you can change the osci yourself. > > First yes sorry I always write XTAL while I mean a complete osc ... ;) > Why : It's not big and when you have a specific frequency for a screen / uart / ... generating > it with the PLL is sometimes annoying ...Yes, a good idea! I will add the spare pads on the back side of the pcb. That does not cost pcb place resources.>>>Other remarks : Having a few I/Os routed as differential pair to the connector could be nice >> >> Do you mean LVDS standard with the termination resistor network? > > Yes, that what I meant. Don't put the resitors by default, just route them as if they were > differential.You mean same lenghth, constant distance. However, there will be almost no routing from the FPGA to the connector. I'll expect only a few mm from pin to connector. Martin ---------------------------------------------- JOP - a Java Processor core for FPGAs: http://www.jopdesign.com/
Reply by ●February 10, 20052005-02-10
Another idea: What do you guys think about adding a slot for a SD Card [1]. They are cheap (about EUR 10,- for 128MB) and you get them up to 1GB! However, the impact on the board is high: The connector is 'big' and increases the board hight. A FPGA with a higher pin-count is needed. For the solution without the SD Card a 100pin TQFP would fit, but now a 144pin is needed - again a larger board. And this adds again a few EUR/$. All these design decissions! You start with a minimal core design and than start adding (unnecesssary) features again. BTW: Has somebody inplemented an SD Card interface in an FPGA. It should not be too hard [2]. The simplest solution would be the SPI bus. [1] http://www.sdcard.org/sd_memorycard/index.html [2] http://www.sandisk.com/pdf/oem/AppNoteMMC_SDv1.0.pdf Martin ---------------------------------------------- JOP - a Java Processor core for FPGAs: http://www.jopdesign.com/ "Martin Schoeberl" <martin.schoeberl@chello.at> schrieb im Newsbeitrag news:sO%Nd.34738$2e4.30046@news.chello.at...> Hi all, > > I'm thinking about a new board for JOP (or MB, NIOS). The board should be small and > cheap (below the S3 Starter Kit). It should only contain the absolute necessary parts for a > CPU design. Here is the suggested part list: > > FPGA: Cyclone EP1C3 or Spartan XC3S200 > 256Kx16 15ns SRAM > 2 MBit serial Flash > 3.3V linear regulation > switching regulator for the core voltage > 20MHz clock to the PLL input > > I've not yet decided about a X or A device. > > A remaining question is about the form factor. I still think it makes sense to build > the board as a module that can be integrated in a board with the peripherals (similar > to the ACEX and Cyclone modules I've done). There are two 'standards' available: > > 1.) SimmStick, where the boards are designed as the 'old' PC SIMMs (see [1]). > > 2.) The 'Basic Stamp' design is a board in the form of an old 40-pin (or less) DIL IC. > An example (from a Java processor competitor): [2] > > For a Java solution in an FPGA this board should beat the Systronix aJ100 Java processor > modules (JStamp or JStick [3] - they have both form factors) in performance and price. > One nice thing about the SimmStick is that there are plenty of I/O boards already available > (see [4, 5, 6]). > It seems a relative 'old' design, but it's a bus and I can build my first JOP cluster with those > boards ;-) > > What do you guys think about this idea? Does it make sense to build a another FPGA board? > > [1] http://www.simmstick.com/ > [2] http://jstamp.systronix.com/jstamp_photos.htm > [3] http://www.jstik.com/ > [4] http://www.dontronics.com/dt.html > [5] http://www.hobbyengineering.com/SectionSS.html > [6] http://www.simmstick.com/simmstic1.htm > > Martin > ---------------------------------------------- > JOP - a Java Processor core for FPGAs: > http://www.jopdesign.com/ >
Reply by ●February 10, 20052005-02-10
Martin Schoeberl wrote:> Another idea: What do you guys think about adding a slot for a SD Card [1]. > They are cheap (about EUR 10,- for 128MB) and you get them up to 1GB! > However, the impact on the board is high: The connector is 'big' and > increases the board hight. A FPGA with a higher pin-count is needed. For > the solution without the SD Card a 100pin TQFP would fit, but now a 144pin > is needed - again a larger board. > And this adds again a few EUR/$. All these design decissions! You start with > a minimal core design and than start adding (unnecesssary) features again. > > BTW: Has somebody inplemented an SD Card interface in an FPGA. It should > not be too hard [2]. The simplest solution would be the SPI bus.You might want to consider two variants: one that is on the KISS path, and is on the lower price knee, and just sufficent to operate a workable JOP, and another that is more maximal, and more able to launch an operating system as well. For package, I'd vote against pin-modules, as they are expensive to make, have a pin count ceiling, and are easily damaged. The only benefit is they can save a little time in first deployment. Better are the memory-card formats, as they have low cost and sturdy connections, that can still be socket managed on 1 & 2 layer PCB, and you can offer a socket-pcb for users starting from nothing. Besides the simmmstick itself, you should consider the SODIMM modules, as seen in TINI : http://www.maxim-ic.com/products/tini/pdfs/TINI_GUIDE.pdf For "smart expansion", SD would be one option, but smaller and more flexible might be USB-Drive ?. Not as cheap at the lowest node, but universally portable - few PCs can R/W SD cards, but they can all R/W a USB drive. Of course, that means the FPGA needs to be smarter :) -jg