A 74HC595 shift register sitting on a Lithuanian 20 euro cents coin.

What is a shift register

The official explanation Well, if you happen to read this page, you are probably wondering what a shift register is. Wikipedia manages to explain it as follows: “a shift register is a cascade of flip flops, sharing the same clock, in which the output of each flip-flop is connected to the ‘data’ input of the next flip-flop in the chain, resulting in a circuit that shifts by one position the ‘bit array‘ stored in it, ‘shifting in’ the data present at its input and ‘shifting out’ the last bit in the array, at each transition of the clock input” Now [ . . . ]