14 Jul
2015
14 Jul
'15
4:58 p.m.
On 7/14/2015 2:56 PM, tony duell wrote:
It will work if you modify it by applying some simple rules, such as I
have described, because I have done so. Of course, it is possible that
I have more rules to uncover. ;)
I would modify that: if you take an existing design created by someone who doesn?t think
about delay
differences, then the FPGA version won?t work. Consider the 6600: at the speeds
involved, you can?t
design in that sloppy fashion. So there are multi phase clocks everywhere, with
consecutive latch points
clocked by the consecutive phases. That means that so long as the max latency is <
the clock phase
difference, it always works.
You are, of course, absolutely correct...
However, such designs are very few and far between. I will guess that if you took just
about any of the
discrete transistor or TTL-baased minis or desktops and fed the design straight into an
FPGA compiler then
it will not work.
-tony