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-rw-r--r--src/cpu/addressing.c152
1 files changed, 72 insertions, 80 deletions
diff --git a/src/cpu/addressing.c b/src/cpu/addressing.c
index 9a1694d..97ebb00 100644
--- a/src/cpu/addressing.c
+++ b/src/cpu/addressing.c
@@ -4,84 +4,61 @@
#include"addressing.h"
-int fAddressGetLength(Addressing addr){
- switch(addr){
- case eAbsolute: case eAbsoluteIndexedX: case eAbsoluteIndexedY:
- return 3;
- case eAccumulator: case eImplied:
- return 1;
- default:
- return 2;
- }
-}
-
-AddData fAddress(Addressing addr, short x) {
- AddData ret;
-
- // ADDRESS
-
- switch(addr){
+address fAddressGetAddress(Addressing mode, short x) {
+ switch(mode){
case eImplied:
case eIndirectAbsolute:
case eRelative:
case eImmediate:
case eAccumulator:
- ret.add = 0x0000;
- break;
-
+ return 0x0000;
case eAbsolute:
- ret.add = x;
- break;
+ return x;
case eAbsoluteIndexedX:
- ret.add = (x + X);
- break;
+ return x + X;
case eAbsoluteIndexedY:
- ret.add = (x + Y);
- break;
-
+ return x + Y;
case eZeroPage:
- ret.add = (x & 0x00FF);
- break;
+ return x & 0x00FF;
case eZeroPageIndexedX:
- ret.add = ((x + X) & 0x00FF);
- break;
+ return ((x + X) & 0x00FF);
case eZeroPageIndexedY:
- ret.add = ((x + Y) & 0x00FF);
- break;
-
+ return ((x + Y) & 0x00FF);
case eIndexedIndirect:
- ret.add = ((getMemory(x+X+1))<<8) + (getMemory(x+X));
- break;
+ return ((getMemory(x+X+1))<<8) + (getMemory(x+X));
case eIndirectIndexed:
- ret.add = ((getMemory(x+1))<<8) + (getMemory(x)) + Y;
- break;
+ return ((getMemory(x+1))<<8) + (getMemory(x)) + Y;
}
+}
- // VALUE
+int fAddressGetLength(Addressing mode){
+ switch(mode){
+ case eAbsolute: case eAbsoluteIndexedX: case eAbsoluteIndexedY:
+ return 3;
+ case eAccumulator: case eImplied:
+ return 1;
+ default:
+ return 2;
+ }
+}
- switch(addr){
+byte fAddressGetValue(Addressing mode, short x, address addr) {
+ switch(mode){
case eImplied:
case eIndirectAbsolute:
case eRelative:
- break;
-
+ return 0;
case eImmediate:
- ret.value = x;
- break;
-
+ return x;
case eAccumulator:
- ret.value = acc;
- break;
-
+ return acc;
default:
- ret.value = getMemory(ret.add);
+ return getMemory(addr);
}
+}
- // LENGTH
-
- ret.length = fAddressGetLength(addr);
-
- // CYCLES
+int fAddressGetCycles(Addressing mode, short x, address addr) {
+ int cycles;
//case &fADC: case &fAND: case &fBIT: case &fCMP: case &fCPX: case &fCPY: case &fEOR: case &fLDA:
//case &fLDX: case &fLDY: case &fORA: case &fSBC: case &fSTX: case &fSTY:
@@ -89,78 +66,78 @@ AddData fAddress(Addressing addr, short x) {
if ( current_instruction == &fADC || current_instruction == &fAND || current_instruction == &fBIT || current_instruction == &fCMP || current_instruction == &fCPX
|| current_instruction == &fCPY || current_instruction == &fEOR || current_instruction == &fLDA || current_instruction == &fLDX || current_instruction == &fLDY
|| current_instruction == &fORA || current_instruction == &fSBC || current_instruction == &fSTX || current_instruction == &fSTY ){
- switch(addr){
+ switch(mode){
case eImmediate:
- ret.cycles = 2; break;
+ cycles = 2; break;
case eZeroPage:
- ret.cycles = 3; break;
+ cycles = 3; break;
case eZeroPageIndexedX: case eAbsolute: case eAbsoluteIndexedX: case eAbsoluteIndexedY:
- ret.cycles = 4; break;
+ cycles = 4; break;
case eIndexedIndirect:
- ret.cycles = 6; break;
+ cycles = 6; break;
case eIndirectIndexed:
- ret.cycles = 5; break;
+ cycles = 5; break;
}
}
//case &fASL: case &fDEC: case &fINC: case &fLSR: case &fROL: case &fROR:
else if( current_instruction == &fASL || current_instruction == &fDEC || current_instruction == &fINC
|| current_instruction == &fLSR || current_instruction == &fROL || current_instruction == &fROR ){
- switch(addr){
+ switch(mode){
case eAccumulator:
- ret.cycles = 2; break;
+ cycles = 2; break;
case eZeroPage:
- ret.cycles = 5; break;
+ cycles = 5; break;
case eZeroPageIndexedX: case eAbsolute:
- ret.cycles = 6; break;
+ cycles = 6; break;
case eAbsoluteIndexedX:
- ret.cycles = 7; break;
+ cycles = 7; break;
}
}
//case &fSTA:
else if (current_instruction == &fSTA){
- switch(addr){
+ switch(mode){
case eZeroPage:
- ret.cycles = 3; break;
+ cycles = 3; break;
case eZeroPageIndexedX: case eAbsolute:
- ret.cycles = 4; break;
+ cycles = 4; break;
case eAbsoluteIndexedX: case eAbsoluteIndexedY:
- ret.cycles = 5; break;
+ cycles = 5; break;
case eIndexedIndirect: case eIndirectIndexed:
- ret.cycles = 6; break;
+ cycles = 6; break;
}
}
//case &fBRK:
else if (current_instruction == &fBRK){
- ret.cycles = 7;
+ cycles = 7;
}
//case &fRTI: case &fRTS: case &fJSR:
else if (current_instruction == &fRTI || current_instruction == &fRTS || current_instruction == &fJSR){
- ret.cycles = 6;
+ cycles = 6;
}
//case &fJMP:
else if (current_instruction == &fJMP){
- ret.cycles = 5;
+ cycles = 5;
}
//case &fPLA: case &fPLP:
else if (current_instruction == &fPLA || current_instruction == &fPLP){
- ret.cycles = 4;
+ cycles = 4;
}
//case &fPHA: case &fPHP:
else if (current_instruction == &fPHA || current_instruction == &fPHP){
- ret.cycles = 3;
+ cycles = 3;
}
else {
- ret.cycles = 2;
+ cycles = 2;
}
@@ -169,15 +146,30 @@ AddData fAddress(Addressing addr, short x) {
//case &fADC: case &fSBC: case &fLDA: case &fLDX: case &fLDY: case &fEOR: case &fAND: case &fORA: case &fCMP:
if ( current_instruction == &fADC || current_instruction == &fSBC || current_instruction == &fLDA || current_instruction == &fLDX || current_instruction == &fLDY
|| current_instruction == &fEOR || current_instruction == &fAND || current_instruction == &fORA || current_instruction == &fCMP ){
- switch(addr){
+ switch(mode){
case eAbsoluteIndexedX:
- if ((x & 0xFF00) != ((x + X) & 0xFF00)) ret.cycles++; break;
+ if ((x & 0xFF00) != ((x + X) & 0xFF00))
+ cycles++;
+ break;
case eAbsoluteIndexedY:
- if ((x & 0xFF00) != ((x + Y) & 0xFF00)) ret.cycles++; break;
+ if ((x & 0xFF00) != ((x + Y) & 0xFF00))
+ cycles++;
+ break;
case eIndirectIndexed:
- if ((ret.add & 0xFF00) != (ret.add - Y & 0xFF00)) ret.cycles++; break;
+ if ((addr & 0xFF00) != (addr - Y & 0xFF00))
+ cycles++;
+ break;
}
}
+ return cycles;
+}
+
+AddData fAddress(Addressing mode, short x) {
+ AddData ret;
+ ret.add = fAddressGetAddress (mode, x);
+ ret.value = fAddressGetValue (mode, x, ret.add);
+ ret.length = fAddressGetLength (mode, x);
+ ret.cycles = fAddressGetCycles (mode, x, ret.add);
return ret;
} \ No newline at end of file
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-30 10:18:03 +0000