Physical understanding of a clock cycle

digital-logicmicrocontroller

I am a software developer (using high level languages like .NET,C,C++ etc) trying to understand how computers work at a lower level. I never studied any Electrical Engineering at university. I did GCSE Electronics.

I understand conceptually what a clock tick is i.e. tick-phase (low), followed by a
tock-phase (high).

Say I have a simple circuit like this:

Schematic example

Is tick when the current leaves negative and tock when it reaches positive?

Best Answer

Imagine a square pulse.

enter image description here

There are the 'high' and the 'low' state.

There are also 2 edges. The rising edge(transition from low to high) and the falling edge(transition from high to low).

Some inputs are edge triggered, while some are triggered by the state of input.

You can know that by their symbol.

enter image description here

The above flip flop's clock is edge triggered, denoted by the triangle and activates on rising edge. The other inputs, S and R, are determined by their state, ie. high and low.

enter image description here

While the above's clock uses the falling edge, denoted by the circle.

So the ticks and tocks are different for each device.