Experiment 4 - The Asynchronous Inputs

For shift register the reset input is especially important. With this input, you are put in a position to put the entire shift register to "0" (or "1").

For the RESET input you use the asynchronous inputs of the flip-flops.

• SET (S)- set the output Q = 1
• RESET (R)- set the output Q = 0

It is important that they are asynchronous inputs. A D-flip-flop can be switched through the asynchronous inputs, independent of the clock signal (Clk)...

Circuit diagram asynchronous inputs D-flip flops.

Circuit asynchronous inputs D-flip flops. (Enlarge)

In the next experiment you integrate the RESET input into the 4-bit shift register...