deciding capacitor & resistor values

Answering your generic question is not possible in this forum because the complete answer is huge. I suggest you start your electrical engineering course of study at a good university and then practice circuit design as a student and professional. It will take years to learn it.

In your example, I'll bet the 22 ohm resistor is for impedance matching. It should tame the clock edges for a reliable clock distribution system.

JJS

I repeat what John Speth said about getting an engineering education -- there's an enormous amount of detail to learn.

If you _do_ have that degree and you're _still_ at a loss, feel free to ask specific questions, like "what is this resistor for?"

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com

You might also search for some old (1970's) ECL design handbooks. In those days 100 MHz was considered as real high tech. While 100 MHz is common these days, the physics has not changed, so check the old literature. This literature was originally written for engineers of the time without RF experience.

In the search term, use "ECL 10000" and you will get quite a lot of hits, find one concerning PCB design.

In this specific case, the value was picked either:

1) As a rule of thumb, because the designer didn't know any better or because it isn't a critical part of the design.

or

2) Because they simulated the PCB and that value was what the simulation showed best matched the PCB layout. To do this you use tools like HyperLynx with IBIS (for example) models of the pins of the CPU, DRAM, etc.

If this is the clock to DDR3 then I would hope approach 2) was taken.

Theo