mirror of https://github.com/bsnes-emu/bsnes.git
90 lines
2.2 KiB
C++
90 lines
2.2 KiB
C++
#include <md/md.hpp>
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namespace MegaDrive {
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CPU cpu;
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auto CPU::Enter() -> void {
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cpu.boot();
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while(true) scheduler.synchronize(), cpu.main();
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}
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auto CPU::boot() -> void {
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r.a[7] = readWord(0) << 16 | readWord(2) << 0;
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r.pc = readWord(4) << 16 | readWord(6) << 0;
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}
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auto CPU::main() -> void {
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#if 0
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static file fp;
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if(!fp) fp.open({Path::user(), "Desktop/tracer.log"}, file::mode::write);
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fp.print(pad(disassemble(r.pc), -60, ' '), " ", disassembleRegisters().replace("\n", " "), "\n");
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#endif
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if(state.interruptPending) {
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if(state.interruptPending.bit((uint)Interrupt::HorizontalBlank)) {
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if(4 > r.i) {
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state.interruptPending.bit((uint)Interrupt::HorizontalBlank) = 0;
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return exception(Exception::Interrupt, Vector::HorizontalBlank, 4);
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}
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}
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if(state.interruptPending.bit((uint)Interrupt::VerticalBlank)) {
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if(6 > r.i) {
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state.interruptPending.bit((uint)Interrupt::VerticalBlank) = 0;
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return exception(Exception::Interrupt, Vector::VerticalBlank, 6);
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}
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}
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}
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instruction();
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}
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auto CPU::step(uint clocks) -> void {
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while(wait) {
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Thread::step(1);
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synchronize();
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}
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Thread::step(clocks);
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synchronize();
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}
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auto CPU::synchronize() -> void {
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synchronize(apu);
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synchronize(vdp);
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synchronize(psg);
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synchronize(ym2612);
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for(auto peripheral : peripherals) synchronize(*peripheral);
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}
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auto CPU::raise(Interrupt interrupt) -> void {
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if(!state.interruptLine.bit((uint)interrupt)) {
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state.interruptLine.bit((uint)interrupt) = 1;
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state.interruptPending.bit((uint)interrupt) = 1;
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}
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}
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auto CPU::lower(Interrupt interrupt) -> void {
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state.interruptLine.bit((uint)interrupt) = 0;
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state.interruptPending.bit((uint)interrupt) = 0;
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}
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auto CPU::power() -> void {
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M68K::power();
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}
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auto CPU::reset() -> void {
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M68K::reset();
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create(CPU::Enter, system.colorburst() * 15.0 / 7.0);
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memory::fill(&state, sizeof(State));
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}
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auto CPU::readByte(uint24 addr) -> uint16 { return bus.readByte(addr); }
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auto CPU::readWord(uint24 addr) -> uint16 { return bus.readWord(addr); }
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auto CPU::writeByte(uint24 addr, uint16 data) -> void { return bus.writeByte(addr, data); }
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auto CPU::writeWord(uint24 addr, uint16 data) -> void { return bus.writeWord(addr, data); }
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}
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