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?

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    Beside being way to broad to be answered in a single question (it asks for the whole development process, as debuging is an integral part to all steps), ti's rather something for EE, as tocpic and answer isn't confined to retrocomputing. – Raffzahn Aug 1 '18 at 13:55
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    Since when do answers need to be confined to retrocomputing? For example we've got the questions about using floppy disks today, or power connectors. – OmarL Aug 1 '18 at 17:13
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    I understand and know that debugging is a broad topic, but I was just hoping for a basic description of the process -- at least I'm asking for a specific type of CPU, the 486. – AlphaCentauri Aug 1 '18 at 18:16
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    @Tommy No, "a better destination" on another site isn't grounds to close a question as off-topic. A question can be on-topic for multiple sites, not just the "best" one. To use the "belongs on another site" close reason it must be off-topic for this site even if the other site doesn't exist. A lot of programming related retrocomputing questions would be on topic here and on Stack Overflow, for example. See "Don't migrate for the sake of migration": meta.stackexchange.com/questions/10249/… – Ross Ridge Aug 1 '18 at 23:03
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    @Tommy The answer to the Meta question I linked explains how the "belongs on another site" close reason is supposed to be used. "Don't migrate for the sake of migration. We only migrate questions because they are off-topic on the original site. It is perfectly possible for a question to be on-topic on multiple sites, but that is not a reason to migrate it elsewhere, unless the OP requests migration. As a general rule, if someone asks a question here, and it's on-topic here, it should stay here." Nowhere does it say it should be used because you think it would be "better" somewhere else. – Ross Ridge Aug 2 '18 at 2:47