Re: Update on Carte Blanche status.

[Alex Freed <alex_news@mirrow.com>]

Steven Hirsch wrote:
> Alex Freed wrote:
>
> > At the same time the re-configuring is a little dangerous just like 
> > re-flashing a motherboard BIOS. If something goes wrong during the 
> > procedure - a power failure or some other malfunction - it can "brick" 
> > the board and the only way to unbrick will be by using the $12 JTAG 
> > tool. Or a $300 USB JTAG from Xilinx :)
>
> Is the $12 tool the "JTAG 3" that connects to a parallel port?  If not, 
> do you know if the latter will server?

The $12 cable is basically the classic design published by Xilinx but 
with a level converter attached that can work with the targets requiring 
lower voltages.

http://www.digilentinc.com/Products/Catalog.cfm?NavPath=2,395&Cat=5

I probably have one of the biggest collections of JTAG tools in the 
Silicon Valley because as a consultant I have to work with a lot of 
different devices. So I also tried the honest-to-God Xilinx' parallel 
cable III but it doesn't have the drivers to reliably work with Spartan 
3e. And the $12 cable does while being logically 100% compatible.

Digilent also has their own USB JTAG cable for $39 or so, but 
unfortunately that only works with their own software - OK to load the 
configuration but not supported by the Xilinx tools like ChipScope.

The bottom line is that for professional work with S3e the $300 USB JTAG 
from Xilinx is pretty much the only game in town. But for hobby purposes 
where speed is not very important and you have a PC with a real parallel 
port the $12 cable is just as good.

-Alex.