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Add implementation of ST instruction for the 6809

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-23 23:09:19 +01:00
parent 1e32514e1d
commit 722e7b89c2
2 changed files with 35 additions and 21 deletions
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2
MC6809/inc/mc6809.h
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@ -294,6 +294,8 @@ namespace EightBit {
void swi();
void swi2();
void swi3();
uint8_t st(uint8_t data);
register16_t st(register16_t data);
void tfr(uint8_t data);
register16_t m_d;

54
MC6809/src/mc6809.cpp
View File

@ -320,29 +320,29 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
// ST
// STA
case 0x97: addCycles(4); break; // ST (STA direct)
case 0xa7: addCycles(4); break; // ST (STA indexed)
case 0xb7: addCycles(5); break; // ST (STA extended)
case 0x97: addCycles(4); BUS().write(Address_direct(), st(A())); break; // ST (STA direct)
case 0xa7: addCycles(4); BUS().write(Address_indexed(), st(A())); break; // ST (STA indexed)
case 0xb7: addCycles(5); BUS().write(Address_extended(), st(A())); break; // ST (STA extended)
// STB
case 0xd7: addCycles(4); break; // ST (STB direct)
case 0xe7: addCycles(4); break; // ST (STB indexed)
case 0xf7: addCycles(5); break; // ST (STB extended)
case 0xd7: addCycles(4); BUS().write(Address_direct(), st(B())); break; // ST (STB direct)
case 0xe7: addCycles(4); BUS().write(Address_indexed(), st(B())); break; // ST (STB indexed)
case 0xf7: addCycles(5); BUS().write(Address_extended(), st(B())); break; // ST (STB extended)
// STD
case 0xdd: addCycles(5); break; // ST (STB direct)
case 0xed: addCycles(5); break; // ST (STB indexed)
case 0xfd: addCycles(6); break; // ST (STB extended)
case 0xdd: addCycles(5); Processor::setWord(Address_direct(), st(D())); break; // ST (STD direct)
case 0xed: addCycles(5); Processor::setWord(Address_indexed(), st(D())); break; // ST (STD indexed)
case 0xfd: addCycles(6); Processor::setWord(Address_extended(), st(D())); break; // ST (STD extended)
// STU
case 0xdf: addCycles(5); break; // ST (STU direct)
case 0xef: addCycles(5); break; // ST (STU indexed)
case 0xff: addCycles(6); break; // ST (STU extended)
case 0xdf: addCycles(5); Processor::setWord(Address_direct(), st(U())); break; // ST (STU direct)
case 0xef: addCycles(5); Processor::setWord(Address_indexed(), st(U())); break; // ST (STU indexed)
case 0xff: addCycles(6); Processor::setWord(Address_extended(), st(U())); break; // ST (STU extended)
// STX
case 0x9f: addCycles(5); break; // ST (STX direct)
case 0xaf: addCycles(5); break; // ST (STX indexed)
case 0xbf: addCycles(6); break; // ST (STX extended)
case 0x9f: addCycles(5); Processor::setWord(Address_direct(), st(X())); break; // ST (STX direct)
case 0xaf: addCycles(5); Processor::setWord(Address_indexed(), st(X())); break; // ST (STX indexed)
case 0xbf: addCycles(6); Processor::setWord(Address_extended(), st(X())); break; // ST (STX extended)
// SUB
@ -470,14 +470,14 @@ int EightBit::mc6809::execute10(uint8_t opcode) {
case 0x2f: addCycles(5); if (branchLong(BLE())) addCycle(); break; // BLE (LBLE relative)
// STS
case 0xdf: addCycles(6); break; // ST (STS direct)
case 0xef: addCycles(6); break; // ST (STS indexed)
case 0xff: addCycles(7); break; // ST (STS extended)
case 0xdf: addCycles(6); Processor::setWord(Address_direct(), st(S())); break; // ST (STS direct)
case 0xef: addCycles(6); Processor::setWord(Address_indexed(), st(S())); break; // ST (STS indexed)
case 0xff: addCycles(7); Processor::setWord(Address_extended(), st(S())); break; // ST (STS extended)
// STY
case 0x9f: addCycles(6); break; // ST (STY direct)
case 0xaf: addCycles(6); break; // ST (STY indexed)
case 0xbf: addCycles(7); break; // ST (STY extended)
case 0x9f: addCycles(6); Processor::setWord(Address_extended(), st(Y())); break; // ST (STY direct)
case 0xaf: addCycles(6); Processor::setWord(Address_indexed(), st(Y())); break; // ST (STY indexed)
case 0xbf: addCycles(7); Processor::setWord(Address_extended(), st(Y())); break; // ST (STY extended)
// SWI
case 0x3f: addCycles(20); swi2(); break; // SWI (SWI2 inherent)
@ -1101,3 +1101,15 @@ void EightBit::mc6809::tfr(uint8_t data) {
else
referenceTransfer8(reg2) = referenceTransfer8(reg1);
}
uint8_t EightBit::mc6809::st(uint8_t data) {
clearFlag(CC(), VF);
adjustNZ(data);
return data;
}
EightBit::register16_t EightBit::mc6809::st(register16_t data) {
clearFlag(CC(), VF);
adjustNZ(data);
return data;
}