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Corrects 68000 address bus during interrupt acknowledge.

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All unused bits should be 1, not 0.
This commit is contained in:
Thomas Harte
2019-08-03 15:38:36 -04:00
parent a07488cf1b
commit 478f2533b5
2 changed files with 12 additions and 18 deletions
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Processors/68000/Implementation/68000Implementation.hpp
+5 -9
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@@ -234,12 +234,6 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
continue;
case ExecutionState::BeginInterrupt:
#ifdef LOG_TRACE
// should_log = true;
if(should_log) {
printf("\n\nInterrupt\n\n");
}
#endif
active_program_ = nullptr;
active_micro_op_ = interrupt_micro_ops_;
execution_state_ = ExecutionState::Executing;
@@ -1960,10 +1954,12 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
// Mutate neessary internal state — effective_address_[0] is exposed
// on the data bus as the accepted interrupt number during the interrupt
// acknowledge cycle, with the low bit set since a real 68000 uses the lower
// data strobe to collect the corresponding vector byte.
// acknowledge cycle, with all other bits set, including the low bit as
// a real 68000 uses the lower data strobe to collect the corresponding vector byte.
//
// Cf. M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL 5.1.4.
accepted_interrupt_level_ = interrupt_level_ = bus_interrupt_level_;
effective_address_[0].full = 1 | uint32_t(accepted_interrupt_level_ << 1);
effective_address_[0].full = 0xfffffff1 | uint32_t(accepted_interrupt_level_ << 1);
// Recede the program counter to where it would have been were there no
// prefetch; that's where the reading stream should pick up upon RTE.