Thomas Harte
7ef526e2d3
Fix destination decrement.
2022-05-19 15:22:59 -04:00
Thomas Harte
ce7f94559b
Add EXG, ABCD, SBCD.
2022-05-19 15:19:00 -04:00
Thomas Harte
0471decfc8
Implement the complete set of fetch addressing modes.
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Subject to observations: (1) MOVE uses slightly custom versions of many of these for its stores; and (2) PEA and LEA need to do the calculation but not the read, so some of this will be duplicated further. It's either that or include greater conditionality on the path.
2022-05-19 15:03:22 -04:00
Thomas Harte
084d6ca11d
Simplify address handling; add perform patterns for CMP, AND, OR, EOR.
2022-05-19 12:18:47 -04:00
Thomas Harte
274902c3c1
Add to-memory write-back. Am going to reconsider usage of temporary_address_ as noted.
2022-05-19 11:23:26 -04:00
Thomas Harte
f46e7c65c5
Add AddressRegisterIndirect fetches.
2022-05-19 10:47:57 -04:00
Thomas Harte
c6c6213460
Bifurcate the fetch-operand flow.
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Address calculation will be the same, but the fetch will differ. I don't think there's a neat costless way to factor out the address calculations, alas, but I'll see whether macros can save the day.
2022-05-19 10:27:51 -04:00
Thomas Harte
1b87626b82
Move some way towards MOVE.
2022-05-18 21:00:10 -04:00
Thomas Harte
da9fb216b1
Remove setup_operation in favour of doing the equivalent inline.
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... as it'll probably allow me a route to `goto` straight out of there, too. At least, if I can find a sufficiently neat macro formulation.
2022-05-18 16:45:40 -04:00
Thomas Harte
bef12f3d65
Move ExecutionState into Implementation.hpp; use goto to avoid some double switches.
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Re: the latter, yuck. Yuck yuck yuck. But it does mean I can stop going back and forth on how to structure conditionality on effective address generation segueing into fetches without doubling up on tests.
2022-05-18 15:35:38 -04:00
Thomas Harte
aa9e7eb7a2
Codify MOVE's status somewhat, avoid reading write-only operands.
2022-05-17 16:57:33 -04:00
Thomas Harte
f3d3e588fd
Add enough of state to [sort-of] pass the first test.
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i.e. until the processor overruns, as it is permitted to do, and can't handle the second instruction.
2022-05-17 16:51:26 -04:00
Thomas Harte
4a40581deb
Completes performance of NBCD D0.
2022-05-17 16:10:20 -04:00
Thomas Harte
eed2672db5
Add documentation, honour signal_will_perform.
2022-05-17 15:05:11 -04:00
Thomas Harte
84071ac6d0
Implement reset logic, advance as far as actually performing an NBCD on D0 (but not writing it back).
2022-05-17 14:51:49 -04:00
Thomas Harte
1a27eea46c
Establish general pattern for selecting a performance phase and obtaining operands.
2022-05-17 14:08:50 -04:00
Thomas Harte
d0b6451f02
Step gingerly on to fetching operands.
2022-05-17 08:26:35 -04:00
Thomas Harte
2147c5a5f2
Fill in missing #undefs.
2022-05-16 21:02:25 -04:00
Thomas Harte
c7aa4d8b6d
Fix state transitions.
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Confirmed that the 68000 mk 2 now appears correctly to perform a reset.
2022-05-16 21:00:25 -04:00
Thomas Harte
e94efe887c
Switch to use of __COUNTER__.
2022-05-16 20:38:17 -04:00
Thomas Harte
3db2de7478
Works 68000 mk2 into the comparative tests.
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... revealing that I've leant a little too hard on __LINE__.
2022-05-16 20:04:13 -04:00
Thomas Harte
345f7c3c62
Fill in just enough to attempt the reset exception, assuming DTACK rather than VPA or BERR.
2022-05-16 16:57:40 -04:00
Thomas Harte
6f6e466c08
Make a first sketch of the coroutine-esque structure I'm going to experiment with here.
2022-05-16 11:59:03 -04:00
Thomas Harte
b0518040b5
Plants the seek of a 68000 mark 2.
2022-05-16 11:44:16 -04:00
