In a computer, most components are synchronized with a clock.
Not everything is necessarily synchronized with the same clock, though.
Most other components arent able to match this incredible speed.
The clock indicates exactly when a component is supposed to operate.
The exact functionality, of course, depends on the component.
But the basic concept is the same, permanently synchronized with the clocks tick.
In a computer, almost all clocks are signaled with a square wave.
A clock pulse is the peak of the square wave.
Interestingly, nothing uses that peak as the trigger for anything.
Instead, most devices operate specifically on the rising edge of the clock pulse as it activates.
RAM is an interesting exception.
You may know that RAM generations are currently referred to as DDR X.
This DDR term is significant.
It stands for Double Data Rate.
This doubles its bandwidth over the same technology using Single Data Rate.
As bandwidth is a critical part of RAM performance, this DDR tech is now universal in RAM.
Contents
How Does the Clock Pulse Work?
A clock generator generates the clock pulse.
This is typically a carefully shaped quartz crystal with an electrical current passed over it.
One of its intrinsic properties is that it generates a perfectly regular pulse of electricity.
Most clocks tick at 100MHz or 100 million cycles per second.
Some computers feature a second clock that operates at a frequency of 125MHz.
The multiplier multiplies how many pulses there are per second.
One of the key advantages of this is that the multiplier can be adjusted.
It does have some unusual limitations, though.
While it sped up RAM, a school of thought suggests its slowed down CPUs.
The problem with this is the logic.
As things dont necessarily complete on a predictable schedule, you must add a lot of extra verification circuitry.
This makes it difficult to verify if the concept would provide an overall performance boost.
As CPUs get larger and feature density higher, more circuitry is required to provide accurate clocking.
Furthermore, as the Node of CPUs has decreased, the resistance on the smaller wires has increased.
This is a further argument for asynchronous CPUs.
Conclusion
A clock pulse is the peak of a square wave clock signal used for computer synchronization.
Most components specifically use the rising edge of that pulse to operate.
DDR RAM, however, uses both the rising and falling edge of the pulse to operate.
A clock generator, such as a quartz piezo-electric oscillator, generates the pulse.
These pulses are then typically modified by a multiplier to precisely match the desired clock speed.
