Hi,
To anyone making a PCB or updating the design I can add a few suggestions.
Disconnect the HSWAP_EN (pin 206) from 0V.
This stops the FPGA driving all I/O during configuration and should negate the need to disconnect SPI_DOUT from pin 81.
If you need any pins pulled to defined states, you can edit the UCF file and recompile.
If you are buying the XC3S400-4PQ208C FPGA, it is easier to obtainm the RoHS compliant replacement, the XC3S400-4PQG208C!
Also the earlier rev BFQ silicon has a number of bugs that could possibly affect the design, in particular relating to the DCM (Digital Clock Manager). Newer parts are much better. Take a look at the Errata for the Spartan 3.
Adding a 6 pin header for the PIC would allow the cheap PicKIt 2 programmer to be used to program the PIC18LF252, providing you add series resistors to RB6/7.
www.pcbtrain.com 2 layer, 12cm x 12 cm, plated through hole PCB, with solder resist and silksreen on one side, quantity of 50, £9.20 each including VAT.
Hope this helps.
So where can I order my Minimig kit from? :-)
Ian
