Hello
I little bit surprized with such implementation of EN.
For D-type (and any type of flip-flops) EN usually means “clock enable”
and for output tri-state function used OE (“output enable”)
Also D-flop from Behaviora\flops library folder have not EN input…
– Regards,
Vctor
It is interesting about EN pin. Firstly, let understand how a pin work in a symbol.
For ¥-Device, it got 16 pins. But ¥-Device devices may only uses few of them, for example, AND gate uses 9 of them and the rest is assigned a name ¥. (you can confirm that with View > Netlist).
For EN pin, for example, Schmitt trigger device has EN in its symbol. If you force this EN pin with a net name ¥, it is equivalent to unassigned EN pin and in default it become always enable.
Currently, D-flop symbol has no EN pin in its symbol, in default, EN pin assigned a ¥.
Therefore, since Qspice added an EN to D-flop, this symbol still works as its past.
In short, update on 10/06/2023 has no impact in using D-flop from Builtin libraray.
In current status, if you want to have EN active for D-flop, that means you have to create a symbol for that (no built-in symbol with EN yet). Actually, this is also the reason why you see so many symbol “variant”, but basically, they are actually the same device. For example, you see a lot of AND gate, but they are just how many input pins used in creating the symbol.
My intention is only to discuss “Also D-flop from Behaviora\flops library folder have not EN input”, not about it should named as EN or OE.
At last, this is an example of modified D-flop with EN pins.
Output enable is a clearer name. I used EN in the help documentation because that was the name on a logic family that I recently modeled. Since no symbol is supplied, you can use any name you want.
