PEX stands for Parastic Extraction. When we build a circuit on a chip we have an intention in mind, for example an ideal inverter inverts the incoming signal immediately and with no delay.

The reality is that we have various ‘parasitics’ for example unwanted capacitance in the MOSFET’s gates, or unwanted resistance in the connections between the MOSFETs. These parasitics slow the inverter down. We can extract the parasitics so we can model them and take them into account when building larger circuits.

At 22:35 of my #remoticon talk you can hear me explain about parasitic extraction and show a demo with magic.

Course feedback

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.

Jonathan Pallant