Re: [avr-gcc-list] [OT] Need For Speed (FPGA)

[Colin O'Flynn]

Hey,

I've CC'd this to avr-chat, so we can move the discussion over there...

> The silicon is very cheap for what you get, but pay attention to the
> configuration method; some configuration chips are 5x the price of the
> FPGA!

Not if you've got an AVR in your project. I just finished making a bootloader 
for the Xilinx FPGA device. It can load a bitstream file from an external 
DataFLASH memory, as well as loading the AVR device itself. The resident 
bootloader takes 198 words right now, so even if you just have a smallish 
chip like an AtMega88 it isn't taking away that much program memory.

Takes 5 seconds to load a Xilinx Sparten IIE 200K gate device. So it isn't 
that fast if you had a huge device, though there are some tricks you could do 
to improve the speed several times over. Namely it involves a less flexible 
hardware setup, where the data lines are hard-wired together. 

Takes about 35 seconds to download the bitstream over the serial port at 57600 
baud.

There isn't a lot of details yet, but I've put the code in CVS at 
http://sourceforge.net/projects/lubloader/ - though there is no schematic yet 
(Docs still comming) so it will be pretty useless.

 -Colin