Comment by wizzard0
this is an important reminder that all digital electronics is really analog but with good correction circuitry.
and run-time cpu and memory error rates are always nonzero too, though orders of magnitude lower than chip yield rates
CPUs may be very digital inside, but DRAM and flash memory are highly analog, especially MLC flash. DDR4 even has a dedicated training mode [1], during which DRAM and the memory controller learn the quirks of particular data lines and adjust to them, in order to communicate reliably.
[1]: https://www.systemverilog.io/design/ddr4-initialization-and-...