Hi.
I see there is lots of activity here, and I quite fancy doing a computer in FPGA (if I get some time).

I've messed about with CPLD a bit, and that the programming remains during power cycles. However, I have read (unless I have misunderstood) that FPGA forgets when powered off and needs to be re-loaded at power-up.

If this is correct, is there a web page that explains what minimal extra hardware is normally used to "bootstrap" an FPGA circuit?

It would be great to stick one of my 6502 micros (eg. the Acorn Atom) on FPGA but I don't have the basics to understand how to create the hardware.

Any pointers to "simple" pages are welcome. I've Googled but don't seem to find the hardware basics needed for FPGA bootstrap loading.

Thanks for reading.

Grant

Hi Grant, Welcome!

I'm not an expert, but have experience using Xilinx PROMs for configuring their FPGA's. There are other cheaper/better? ways to config the FPGA. Their PROM datasheet and user guide go over this topic.

I've gotten away with using just 2 resistors and PROM in my latest design.

Good Luck!

Wow, thanks.

I'll read through the Xilinx PROM documentation that you have shown. Thanks for the starter (I see some late nights coming up )

Grant

also, note that in the spartan-3 series, there's a non-volatile range which is just a little more expensive - £7 rather than £6 for a 50k gate part.

(I don't think any of us here have direct experience of these)

Edit: also, if you search for the datasheets for the OHO GODIL modules, they contain full schematics.

You can also search for schematic PDFs on DigilentInc's website, for their Xilinx FPGA boards. Good to compare schematics to what Xilinx datasheets tell you....