21 Apr
2011
21 Apr
'11
6:05 p.m.
On 21/04/11 22:02, Tony Duell wrote:
Go look up "ChipScope" and "SignalTap II".
Then tell me you can't spy on the internal logic of an FPGA.
If you really want to use a standalone logic analyser (I often do
because it tends to be more reliable) then there's always the option of
pulling a couple of pins out onto solder pads. The 1.27mm TESTPADs in
the EAGLE base libraries work quite well IME. Big enough to be easy to
solder to, small enough that they don't take up much board space.
The DiscFerret ICSP header is as big as it is for one reason only:
because when you're using pogo pins, you want the alignment to be as
insignificant (or "non-critical" if you prefer) as is technically possible!
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
Drop the
design into an FPGA and you go from several huge boards full of
TTL to one Eurocard, an FPGA, and a couple of RAM chips.
With nowhere to connect the 'scope and logic analyser to debug it, no
interesting signals to look at... Might as well jsut buy a modern PC.