Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

connecting 2 dev kits via HSMC-HSMC?

Hi,

I'd like to use 2 dev kits' FPGAs to simply communicate (w/ as much bandwidth as possible), and I'm looking to at communicating over the HSMC connectors (male-male?).

I only see male-female ribbons out there. Are there any cables available for this (male-male, no power, etc)?

Any problems with or tips for doing this? IO settings(!), clock/data rates, protocols (source sync or not, parallel or serial), etc. I'd like to do better (& simpler) than HSMC->GPIO|SC|mictor & wiring those together.

Any suggestions are appreciated. I'd be content w/ fixed single-direction connections, but would at least like to split up the pins ~evenly in each direction.

-Brian

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    There are male-male cables available (e.g. HQCD series) but not suitable for your application, cause they would also connect the power supplies. To my opinion, the only meaningful option is to use QTH board coennectors, interconnect boards and cables in-between.

    You have different I/O standard and protocol options, depending on the intended throughput. Source synchronous serial highspeed transmission would be e.g. an effective way.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    The HSMC connectors are made by Samtec:

    http://www.samtec.com

    I believe they sell the cable you are looking for. As an example, the Altera NEEK development kit has a flex cable to connect the two HSMC connectors. Check it out.

    Jake
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    Thanks for the replies. Ack, I hoped this was going to be simple.

    Jake, I appreciate the links, they helped me be sure I'm looking at what your referring to. These look like variants of the cable that comes w/ the Neek, which is "male-female". I must lack the imagination to see how to use these to connect 2 devkits together. :)

    FvM, this image makes HQCD also look male-female:

    http://www.samtec.com/ftppub/testrpt/tc0350--0332rev03web_qua.pdf

    I haven't contacted Samtac so maybe you two know that I can special order male-male even if I don't see a pic of it on the site.

    Regardless, I think your confirmation that they'll all be shorting the power makes me worry about how easy or hard it will be to sever the power connections in the ribbon.

    ---

    So... as for using daughter cards to help bridge the connection...

    So far, I'm tempted by things like:

    http://www.kanecomputing.co.uk/bitec_hsmc_proto.htm

    or

    THDB-HTG (HSMC)

    http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&no=322

    Can you forsee any problems if I use the THDB-HTG w/ some IDE cables and just cut the power connection in the cables?

    i.e. Is 'IDE' == 'Altera DE1/DE2' == 'standard 40pin', mechanically speaking?

    I'm still in dev-kit land, so off-the shelf solutions are preferred, even if it limits my performance.

    -Brian
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    obviously this is a pretty old thread but curious if there was ever any resolution - did you get the two dev kits to communicate via the HSMC connector? I know samtec now offers Male to Male HSMC connectors - but there are still power pin issues with certain boards - where the outbound power to the HSMC connector cant be turned off leading one to have to modify the cable so as to not fry the other board.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Steve, I ended up just buying 2 Terasic daughter cards & using IDE (40pin) ribbon cable to selectively connect the IO I wanted. The cables are easy to shorten and reorder/cut traces.

    Eg:

    http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=67&no=218

    or

    http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=67&no=322

    They're $50/$55 each, and that was good enough for what I needed (& avoided touching a soldering iron to any of the dev boards.) Plus, they're just a handy addition for future altera/hsmc debug.

    My other excuse was having an Intronix Logicport logic analyzer ($389, http://www.pctestinstruments.com/ ) which also uses a 40p (IDE ribbon) type of connector. So I already like to use 40p debug headers & have a variety of rewired IDE ribbon cables.

    If you'd rather connect the high speed connections, maybe you could try hsmc to SATA or SMA, like this ($140):

    http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=67&no=129

    Good luck, -B