Re: [hatari-devel] 68030 instruction time calculation formulae

[Douglas Little <doug694@xxxxxxxxxxxxxx>]

Hi!

Unfortunately that information is not low level enough. It can't be used to re-create how CPU internal sequencer exactly works which is the only way to get real cycle-exact emulation. Cache case should be already quite accurate, minus instructions that need internal operation cycles like MUL and DIV and others.

I can see it will be difficult to get everything exact (esp. uncached cases), but historically we've had rather approximate timings for 030 under emulation so the newer core should make a big difference here. I just wasn't sure how much of that info had actually been adopted by UAE - from your message it certainly seems like most of it has.

 

UAE m68k emulator already uses information from both 68020 and 68030 documentation (head/tail/internal cycles). 68030 more or less seems to be 68020 with 1 cycle faster memory access + some small instruction timing changes.

Thanks for clarifying - I haven't spent enough time looking at the emulator in detail. (I have recently been working on instruction scheduling tools so I have more than a passing interest in the subject).

 

I am still not sure when I am going to do it, it will be extremely boring..

Indeed - I can understand that part very well :)

D