[time-nuts] Using CPLD/FPGA or similar for frequency divider

Hal Murray hmurray at megapathdsl.net
Fri Jun 5 23:19:16 EDT 2015


richard at karlquist.com said:
> I used a CPLD in a 900 GHz (that's right 900 GHz) optical sampling scope
> timebase.  It was great because you just write a 17 bit counter in VHDL and
> there it is.  You don't have to know anything about building digital
> hardware any more (40 years of experience wasted). Nobody cares about look
> ahead carry, etc. 

Is that really true?  Or perhaps, what fraction of the digital design space 
does it apply to?

How fast was your counter running?  How fast would it run?  Was it a simple 
counter or was there enable/up/down/load type gating involved?

What would you have done if you needed to run a bit faster?  Could you buy a 
faster chip?  How much more could you get with tricky logic?

I agree that modern tools and parts have allowed a lot more people to build 
digital circuits.



-- 
These are my opinions.  I hate spam.





More information about the time-nuts mailing list