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Minor reorganisation to finish the day.

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This commit is contained in:
Thomas Harte 2021-01-17 21:56:15 -05:00
parent 4982430a29
commit 8a74f5911c
1 changed files with 11 additions and 6 deletions
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17
InstructionSets/M50740/Executor.cpp
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@ -77,10 +77,6 @@ template <Operation operation, AddressingMode addressing_mode> void Executor::pe
address = (memory_[next8()] | (memory_[(next8()+1)&0xff] << 8)) + y_;
break;
case AddressingMode::Relative:
address = program_counter_ + size(addressing_mode) + int8_t(next8());
break;
case AddressingMode::AbsoluteIndirect:
address = next16();
address = memory_[address] | (memory_[(address + 1) & 0x1fff] << 8);
@ -96,6 +92,11 @@ template <Operation operation, AddressingMode addressing_mode> void Executor::pe
BitXZeroPageRelative
*/
case AddressingMode::Relative:
address = program_counter_ + size(addressing_mode) + int8_t(next8());
// TODO: should be a special case; doesn't become a read, write or read-modify-write.
break;
default:
assert(false);
}
@ -106,6 +107,9 @@ template <Operation operation, AddressingMode addressing_mode> void Executor::pe
program_counter_ += 1 + size(addressing_mode);
assert(access_type(operation) != AccessType::None);
// TODO: full reading/writing logic here; only the first 96 bytes are RAM,
// there are also timers and IO ports to handle.
if constexpr(access_type(operation) == AccessType::Read) {
perform<operation>(&memory_[address & 0x1fff]);
return;
@ -114,10 +118,11 @@ template <Operation operation, AddressingMode addressing_mode> void Executor::pe
uint8_t value = memory_[address & 0x1fff];
perform<operation>(&value);
// TODO: full writing logic here; only the first 96 bytes are RAM,
// there are also timers and IO ports to handle.
memory_[address & 0x1fff] = value;
}
template <Operation operation> void Executor::perform(uint8_t *operand [[maybe_unused]]) {
switch(operation) {
default: assert(false);
}
}