An Integrated Circuit is a collection of circuit elements all together on one piece of silicon.
Example elements include:
- transistors, for example MOSFETS
Here is an example of a fairly small IC, a type of amplifier called an Op-Amp.
The image is from zeptobars
The orange zig-zag elements are resistors, the large areas at the top are capacitors, the squares with circular elements in their centres are bipolar transistors, and the thin silver elements are wires joining these components together. Such a circuit could have been made using discrete components on a circuit board, but it would have higher cost and lower performance. By integrating all of these elements together, the cost and performance are improved.
From wikipedia: There is no consensus on who invented the IC. The American press of the 1960s named four people: Kilby, Lehovec, Noyce and Hoerni; in the 1970s the list was shortened to Kilby and Noyce.
The part I enjoyed the most was going back to the Verilog and seeing test benches pass. In particular the waveform viewer. At the latter parts of course you're simulating the entire Caravel system on chip with a RISCV core. Being able to drill down into everything inside that core, I can log the program counter, I can log all the address and data buses and you can just see in exquisite detail what the system is doing, and it's doing that because I programmed it. Being able to drill down into that detail was really fascinating.