How was the Intel 80486 (from 1989) debugged? I'm assuming it was written in some HDL language, like Verilog. However, how was testing and debugging of the CPU carried out?
Were there several steps to this process, such as running it in an emulator at first, then simulating the Verilog code, then testing manufactured prototype CPUs?
What tests were used?
As a bonus question, are there big differences in how this was done in the late 80s to how it is done today?