mirror of https://github.com/bsnes-emu/bsnes.git
42 lines
891 B
C++
42 lines
891 B
C++
auto CPU::io() -> void {
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cycleEdge();
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step(4);
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}
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auto CPU::read(uint16 addr) -> uint8 {
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cycleEdge();
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step(4);
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return bus.read(addr);
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}
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auto CPU::write(uint16 addr, uint8 data) -> void {
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cycleEdge();
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step(4);
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bus.write(addr, data);
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}
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auto CPU::cycleEdge() -> void {
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if(r.ei) {
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r.ei = false;
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r.ime = 1;
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}
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}
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//VRAM DMA source can only be ROM or RAM
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auto CPU::readDMA(uint16 addr) -> uint8 {
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if(addr < 0x8000) return bus.read(addr); //0000-7fff
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if(addr < 0xa000) return 0xff; //8000-9fff
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if(addr < 0xe000) return bus.read(addr); //a000-dfff
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return 0xff; //e000-ffff
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}
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//VRAM DMA target is always VRAM
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auto CPU::writeDMA(uint16 addr, uint8 data) -> void {
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addr = 0x8000 | (addr & 0x1fff); //8000-9fff
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return bus.write(addr, data);
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}
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auto CPU::readDebugger(uint16 addr) -> uint8 {
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return bus.read(addr);
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}
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