[Libre-soc-dev] AON21 : the solution to the set/reset flip-flop

whygee at f-cpu.org whygee at f-cpu.org
Thu Aug 13 19:37:37 BST 2020


Some months ago (?) I read that there "needed" to be a new gate design
to implement the set-reset latches for the scheduler/scoreboard.
I have not seen any follow-up but it just strikes me now :

This is available under Alliance and others.

Just loop the Z output to the A2 input and you're done.
SET is the B input and A1 is a (negative) reset input.
SET has priority, you can change this by using
or even better :
(smaller and with positive RESET)

If you want to have extra optimisation points, you could
loop with a poly wire (to save some metal routing) and remove
the looped A input from the gate description to prevent error messages.

No idea if this helps right now but it's good to know :-)


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