Re: A look at the C-One (Commodore One) reconfigurable computer

["Kryten" <kryten_droid_obfusticator@ntlworld.com>]

"Mark McDougall" <msmcdoug@no.spam.iinet> wrote in message 
news:41fffd63$0$15100$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

> Umm, you'll find that the FPGA probably requires a serial bitstream to 
> configure. So you'd have to at least have a state machine in a CPLD that 
> bit-bashes the config pins on the device.

No problem, but not essential.

The Xilinx chip I use can be configured by a stream of bytes.

> And if you're planning on storing the config image in a flash ROM, you'll 
> need to drive the flash addressing without a large pin count on your CPLD 
> (say, a counter?!?).

When configuring, the CPU provides the sequence of flash addresses.

If I ever want to change the flash contents, I just boot up the system and 
tell the CPU to reprogram the flash ROM.

That's how I managed to program my flash ROM without a programmer.
I loaded my FPGA (via JTAG) with a minimal system and BASIC ROM in the FPGA.
Then I just downloaded a BASIC program to program the Flash.

Cute trick huh?

> Of course Altera have flash-based config devices especially for this 
> purpose, but they're expensive and programmed via JTAG.

JTAG is no problem.

> "Electrical Engineers do it with less resistance!"

Mechanical engineers find women with the most streamlined bodies put up the 
most resistance.