25-02-2017, 05:53 PM
(24-02-2017, 09:55 AM)ppppenguin Wrote: In the early 1990s I started to use Xilinx FPGAs. Starting with the 3000 series, devices that contained just a few dozen flipflopsHi Jeffery
That’s unheard of! Or at least it is to me. I always thought of FPGA's of having gazillions of devices in them. You certainly have seen some changes over a relatively short time. One thing about FPGA's that seems odd is that most of them appear to require external program memory. It would seem more convenient if they had it internally but no doubt they have a good reason for doing it that way.
I was having a look for documentation on Quartus Prime schematic entry and in particular on the symbols but haven’t found any. There is plenty of documentation on Quartus Prime but it all relates to HDL, which I guess is understandable.
I suspect the reset inputs on the flip flops are synchronous as the schematic entry appears to be designed to be pretty idiot proof, with probably, having the trade off of being restrictive compared to HDL.
Frank
