[flying_sheep]

First of all you must understand logic gates, flip-flops (D-FF, T-FF and so on) and multiplexers. All of them are built on logic gates. To verify that you really understand the concept, try to implement a digital clock. (This one: https://sapling-inc.com/wp-content/gallery/digital-clocks-fo...)

Logic gates are essential of learning digital circuits. After you understand logic gates, you can use it to build many things that are really related to the application. There are many tools to verify the logic gates works as designed.

Then based on the project requirement ($$, time, performance, ...), you can choose to use FPGA or ASIC to implement logic gates. FPGA use array of logic gates while ASIC uses CMOS to implement the logic gates. FPGA is easier to learn and much cheaper. You can buy some development board which costs only several hundred dollars. While ASIC needs much domain knowledge and people involved. ASIC needs you to understand the electronics in order to build something that is useful. You need to understand how the CMOS are implemented (= how semiconductor becomes conductive), how the resistance and capacitance affect the performance, the number of wafer layout which affects the cable layout and more. And don't forget manufacturing can introduce defeats which cause the IC to malfunction in unexpected ways. Each step in ASIC needs a specialist for them

[forg0t_username]

For 5 seconds I was like "but the clock is the analog part of the circuit, this does not make any sense". Then I clicked the link.