SimmStick FPGA module

From: Martin Schoeberl (
Date: 02/08/05

Date: Tue, 08 Feb 2005 09:40:40 GMT

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?


JOP - a Java Processor core for FPGAs: