diff options
Diffstat (limited to 'instruction.h')
| -rw-r--r-- | instruction.h | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/instruction.h b/instruction.h index bdb337c..b296e0c 100644 --- a/instruction.h +++ b/instruction.h @@ -4,14 +4,16 @@ // how many cycles passed struct instruction_data { - int length; - int cycles; + int length = 0; + int cycles = 0; }; int getLength(Addressing addr){ switch(addr){ - case eZeroPage: case eZeroPageIndexedX: case eZeroPageIndexedY: + case eAbsolute: case eAbsoluteIndexedX: case eAbsoluteIndexedY: return 3; + case eAccumulator: + return 1; default: return 2; } @@ -21,34 +23,45 @@ int getLength(Addressing addr){ // Load and Store Instructions instruction_data fLDA(Addressing addr, address val){ - acc = fAddressing(addr, val); instruction_data d; d.length = getLength(addr); - + acc = fAddressing(addr, val); + return d; } instruction_data fLDX(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); X = fAddressing(addr, val); + return d; } instruction_data fLDY(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); Y = fAddressing(addr, val); + return d; } instruction_data fSTA(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); Memory[(fAddressing(addr, val))] = acc; + return d; } instruction_data fSTX(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); Memory[(fAddressing(addr, val))] = X; + return d; } instruction_data fSTY(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); Memory[(fAddressing(addr, val))] = Y; + return d; } // Arithmetic Instructions instruction_data fADC(Addressing addr, address val){ + instruction_data d; d.length = getLength(addr); int buffer = acc + fAddressing(addr, val); setFlagV(buffer, acc); @@ -138,39 +151,39 @@ instruction_data fEOR(Addressing addr, address val){ // Jump, Branch, Compare, and Test Bits instruction_data fJMP(address val){ - S = val; + PC = val; } instruction_data fBCC(signed char val){ - if (getFlag(flag_C) == 0) S += val; + if (getFlag(flag_C) == 0) PC += val; } instruction_data fBCS(signed char val){ - if (getFlag(flag_C) == 1) S += val; + if (getFlag(flag_C) == 1) PC += val; } instruction_data fBEQ(signed char val){ - if (getFlag(flag_Z) == 1) S += val; + if (getFlag(flag_Z) == 1) PC += val; } instruction_data fBNE(signed char val){ - if (getFlag(flag_Z) == 0) S += val; + if (getFlag(flag_Z) == 0) PC += val; } instruction_data fBMI(signed char val){ - if (getFlag(flag_N) == 1) S += val; + if (getFlag(flag_N) == 1) PC += val; } instruction_data fBPL(signed char val){ - if (getFlag(flag_N) == 0) S += val; + if (getFlag(flag_N) == 0) PC += val; } instruction_data fBVS(signed char val){ - if (getFlag(flag_V) == 1) S += val; + if (getFlag(flag_V) == 1) PC += val; } instruction_data fBVC(signed char val){ - if (getFlag(flag_V) == 0) S += val; + if (getFlag(flag_V) == 0) PC += val; } instruction_data fCMP(address val){ |