Flip-Flops & Counters

Sequential logic — circuits that remember. Click the clock to advance, toggle inputs, watch the state change. Build a 4-bit counter from flip-flops.

SR Latch: Set-Reset latch. S=1 sets Q to 1. R=1 resets Q to 0. Both S=R=1 is forbidden (undefined behavior). The most basic memory element.
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