mirror of https://github.com/bsnes-emu/bsnes.git
81 lines
1.8 KiB
C++
81 lines
1.8 KiB
C++
//immediate, 2-cycle opcodes with idle cycle will become bus read
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//when an IRQ is to be triggered immediately after opcode completion.
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//this affects the following opcodes:
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// clc, cld, cli, clv, sec, sed, sei,
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// tax, tay, txa, txy, tya, tyx,
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// tcd, tcs, tdc, tsc, tsx, txs,
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// inc, inx, iny, dec, dex, dey,
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// asl, lsr, rol, ror, nop, xce.
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auto WDC65816::idleIRQ() -> void {
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if(interruptPending()) {
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//modify I/O cycle to bus read cycle, do not increment PC
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read(PC);
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} else {
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idle();
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}
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}
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auto WDC65816::idle2() -> void {
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if(lo(D)) idle();
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}
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auto WDC65816::idle4(uint16 x, uint16 y) -> void {
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if(!XF || hi(x) != hi(y)) idle();
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}
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auto WDC65816::idle6(uint16 addr) -> void {
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if(EF && hi(PC) != hi(addr)) idle();
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}
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auto WDC65816::fetch() -> uint8 {
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return read(db(PC) << 16 | aa(PC)++);
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}
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auto WDC65816::pull() -> uint8 {
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EF ? lo(S)++ : S++;
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return read(S);
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}
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auto WDC65816::push(uint8 data) -> void {
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write(S, data);
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EF ? lo(S)-- : S--;
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}
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auto WDC65816::pullN() -> uint8 {
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return read(++S);
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}
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auto WDC65816::pushN(uint8 data) -> void {
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write(S--, data);
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}
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auto WDC65816::readDirect(uint addr) -> uint8 {
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if(EF && !lo(D)) return read(D | uint8(addr));
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return read(uint16(D + addr));
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}
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auto WDC65816::writeDirect(uint addr, uint8 data) -> void {
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if(EF && !lo(D)) return write(D | uint8(addr), data);
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write(uint16(D + addr), data);
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}
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auto WDC65816::readDirectN(uint addr) -> uint8 {
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return read(uint16(D + addr));
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}
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auto WDC65816::readBank(uint addr) -> uint8 {
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return read((B << 16) + addr);
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}
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auto WDC65816::writeBank(uint addr, uint8 data) -> void {
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write((B << 16) + addr, data);
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}
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auto WDC65816::readStack(uint addr) -> uint8 {
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return read(uint16(S + addr));
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}
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auto WDC65816::writeStack(uint addr, uint8 data) -> void {
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write(uint16(S + addr), data);
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}
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