6502/EightBit
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Reuse pul/psh definition to simplify entire register set save/restore code.

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-10-17 20:42:03 +01:00
parent 4b2f8e3599
commit 966a07b018
1 changed files with 8 additions and 25 deletions
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33
MC6809/src/mc6809.cpp
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@ -61,7 +61,7 @@ void EightBit::mc6809::handleNMI() {
setFlag(CC(), IF); // Disable IRQ
setFlag(CC(), FF); // Disable FIRQ
jump(getWordPaged(0xff, NMIvector));
addCycles(21);
addCycles(12);
}
void EightBit::mc6809::handleIRQ() {
@ -71,7 +71,7 @@ void EightBit::mc6809::handleIRQ() {
saveEntireRegisterState();
setFlag(CC(), IF); // Disable IRQ
jump(getWordPaged(0xff, IRQvector));
addCycles(21);
addCycles(12);
}
void EightBit::mc6809::handleFIRQ() {
@ -219,7 +219,7 @@ void EightBit::mc6809::executeUnprefixed(const uint8_t opcode) {
case 0x73: addCycles(7); BUS().write(com(AM_extended_byte())); break; // COM (extended)
// CWAI
case 0x3c: addCycles(20); cwai(AM_direct_byte()); break; // CWAI (direct)
case 0x3c: addCycles(11); cwai(AM_direct_byte()); break; // CWAI (direct)
// DAA
case 0x19: addCycles(2); A() = da(A()); break; // DAA (inherent)
@ -433,7 +433,7 @@ void EightBit::mc6809::executeUnprefixed(const uint8_t opcode) {
case 0xb3: addCycles(7); D() = sub(D(), AM_extended_word()); break; // SUB (SUBD extended)
// SWI
case 0x3f: addCycles(19); swi(); break; // SWI (inherent)
case 0x3f: addCycles(10); swi(); break; // SWI (inherent)
// SYNC
case 0x13: addCycles(4); halt(); break; // SYNC (inherent)
@ -540,7 +540,7 @@ void EightBit::mc6809::execute10(const uint8_t opcode) {
case 0xbf: addCycles(7); Processor::setWord(Address_extended(), st(Y())); break; // ST (STY extended)
// SWI
case 0x3f: addCycles(20); swi2(); break; // SWI (SWI2 inherent)
case 0x3f: addCycles(11); swi2(); break; // SWI (SWI2 inherent)
default:
UNREACHABLE;
@ -569,7 +569,7 @@ void EightBit::mc6809::execute11(const uint8_t opcode) {
case 0xbc: addCycles(8); cmp(S(), AM_extended_word()); break; // CMP (CMPS, extended)
// SWI
case 0x3f: addCycles(20); swi3(); break; // SWI (SWI3 inherent)
case 0x3f: addCycles(11); swi3(); break; // SWI (SWI3 inherent)
default:
UNREACHABLE;
@ -740,14 +740,7 @@ EightBit::register16_t EightBit::mc6809::AM_extended_word() {
void EightBit::mc6809::saveEntireRegisterState() {
setFlag(CC(), EF); // Entire flag set saved
pushWordS(PC());
pushWordS(U());
pushWordS(Y());
pushWordS(X());
pushS(DP());
pushS(B());
pushS(A());
pushS(CC());
psh(S(), 0xff);
}
//
@ -1043,17 +1036,7 @@ uint8_t EightBit::mc6809::ror(uint8_t operand) {
}
void EightBit::mc6809::rti() {
CC() = popS();
if (CC() & EF) {
addCycles(9); // One cycle per byte
A() = popS();
B() = popS();
DP() = popS();
X() = popWordS();
Y() = popWordS();
U() = popWordS();
}
rts();
pul(S(), CC() & EF ? 0xff : 0b10000001);
}
void EightBit::mc6809::rts() {