SR Latch confirmation needed

Thread Starter


Joined Sep 18, 2007
in an SR latch, S=1, R=0 so Q=1 Q'=0, then S=0, R=0 and since that's the "latch" state, Q=1 and Q'=0 right? the S=0 and R=0 just means that Q and Q' stay unchanged or does it reset to it's initial state?

I did indeed read before I posted this, just wanting to make sure I understand it.
Last edited:


Joined Feb 4, 2008
If you are talking about a NOR gate RS latch, if R=0 and S=0 then Q and Q' stays unchanged (holds the previous value). For a NAND gate RS latch things work a bit different.

Have a look here, it will help you:

You can click on the blue squares on the latch inputs and play with it.