Experiment 7 - The Clock Input

During the time that a latch is open, the inputs can influence the result at any time. In modern applications, where many latches work together, this is no longer desirable. You want that all latches find their results at exactly the same time.

To achieve this you need two things ...

• a synchronous signal and
• a latch, which changes its result only at a specific point in time .

The role of a synchronous signal is taken over by the clock signal. It switches at periodic intervals between the states 0 and 1...

Clock Signal.

The clock cycle is the time of one transition from 0 to 1 to the next. The clock rate or frequency is the number of cycles per second and is measured in Hertz (Hz).

Now if you connect the clock signal to the E input, the latch is periodically opened and closed. And if you connect several latches to the same clock signal, they are opened and closed synchronously.

In the next step you learn what an edge-triggered latch is.