[oc] Modular FPGA Board: Block Diagram

[John Dalton <john.dalton@southern-poro.com>]

Apologies if you get two of this.  The first one seems to be lost.
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I have put together a block diagram of a possible configuration
for the modular FPGA board.  It is available on the web at:

http://www.elec.mq.edu.au/~jdalton/modularfpga/

Both BMP and postscript format are available (but the postscript
may be bad).

Some comments:

1) The board contains a range of SIMM/DIMM connectors
from 30 to 168 pins

2) The DIMM may have to go (in version 1) if it proves too
difficult to route in a limited number of layers.

3) It remains to be seen if that many sockets can fit on
a reasonable sized board.

4) The PCI style edge connector is intended to plug into a second interface
board (Which may implement PCI, ISA, EISA, SCSI,  whatever...)
Having SIMMs on the PCI tracks may cause impedance
mismatches on a PCI bus, but it allows the POSSIBILITY of
doing a PCI interface in the main chip. If strict compliance
is necessary, the user may have to build a plug in board
with an FPGA containing the PCI interface and minimum
length tracks to a second PCI connector.

5) Only the bare minimum is on the main board.  All peripherals
belong on modules.


Please have a look at this diagram and pass any comments onto me.

Regards
John