We've had a look at what's inside the ATMega328 and discussed the various pieces. The '328 is a simple, 8-bit MCU. Even so, it is representative of most MCUs you will find; they all have the same basic components although their size, capabilities, and/or complexity will vary.
Now that we have a general understanding, let's deepen it. How? By designing and building one, of course. We're makers, after-all... let's make an MCU! That will be done in the next tutorial in this series. See you next time.