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Circuit Description

This circuit demonstrates the basic SR (for set-reset) flipflops built from NAND and NOR gates. The typical structure of both circuits are the feedback lines that connect the output of one gate back to the input of the other gate.

The behavior of both circuits is very similar; the most important feature is that the circuits are able to store information. Please play with the circuits and compare the simulation with the function (or state) tables on the right of the schematics.

In all normal states, the output of the two gates are inverse to each other, which means that a flipflop circuit can generate both the Q output value and the inverted NQ output value at no extra cost. Naturally, the so called forbidden states don't damage the circuit, but they should be avoided because in those states the outputs of the two gates are not complementary to each other.