[alexeldeib]

A peer mentioned different types of memory and flip flops. I’d search for JK flip flop or D flip flop/latch for conceptual pointers. Those can be used to build up register files. The logic gates used to build flip flops/latches use things like NMOS/CMOS/PMOS - different kind of metal oxide seniconductor logic based on substrate. The differing behavior affects how you arrange circuits (voltage source, ground, etc) to provide desired logic from inputs (keywords: pull down/pull up network). Once you have logic and memory, you can build control units and things like arithmetic logic (look up von Neumann/Harvard architecture).

I’m not an expert in modern hardware, but these are the basic principles I recollect. Happy to be corrected if this answer is dated :)

[dreamcompiler]

The standard decomposition is

--The instruction set is the lowest level of user-visible software. The instruction set is implemented (in principle) by microcode.

--Microcode (if present) is a bunch of hardwired logic signals that cause data to move between subunits of the CPU in response to instructions. Register transfer specifications govern the design at this level.

--A CPU is a collection of subunits including registers, arithmetic units, and logic gates.

--Registers are collections of flip-flops.

--Arithmetic units are made of logic gates.

--Flip-flops are made from logic gates in feedback configurations to make them stateful. State machine theory governs the design of these circuits.

--Logic gates are stateless and made of transistors. Boolean algebra governs the design at this level.

--Transistors are made of NMOS or PMOS or bipolar silicon junctions. Device physics and electrical properties govern this level.

This abstraction hierarchy is useful when learning, but in the real world the abstraction layers are much blurrier: Everything's really just transistors, stateless stuff often has invisible state, electrical considerations matter at every level, etc.