109 lines
2 KiB
C++
109 lines
2 KiB
C++
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#include "cpu/cpu.h"
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u8 Cpu::readPC8()
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{
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u8 data = bus->read8(state.PC);
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state.PC++;
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return data;
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}
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u16 Cpu::readPC16()
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{
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u16 data = bus->read16(state.PC);
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state.PC+=2;
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return data;
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}
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void pushStack8(u8 data)
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{
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bus->write8(state.SP, data);
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state.SP--;
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}
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u8 popStack8()
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{
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u8 data = bus->read8(state.SP);
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state.SP++;
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return data;
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}
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void pushStack16(u16 data)
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{
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bus->write16(state.SP,data);
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state.SP-=2;
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}
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void popStack16()
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{
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u16 data = bus->read16(state.SP);
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state.SP+=2;
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return data;
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}
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void Cpu::step()
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{
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opcode_t op = readPC();
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int mcycles = 1;
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switch(op) {
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0x00: // NOP
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(void) ;;
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0x01: // LD BC, n16
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state.BC = readPC16(); mcycles = 12;;
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0x11: // LD DE, n16
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state.DE = readPC16(); mcycles = 12;;
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0x21: // LD HL, n16
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state.HL = readPC16(); mcycles = 12;;
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0x31: // LD SP, n16
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state.SP = readPC16(); mcycles = 12;;
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0x02: // LD [BC], A
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bus->write8(state.BC, state.A); mcycles = 8;;
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0x12: // LD [DE], A
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bus->write8(state.DE, state.A); mcycles = 8;;
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0x22: // LD [HL+], A
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bus->write8(state.HL, state.A); state.HL++; mcycles = 8;;
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0x32: // LD [HL-], A
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bus->write8(state.HL, state.A); state.HL--; mcycles = 8;;
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0x03: // INC BC
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state.BC++; mcycles = 2;;
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0x13: // INC DE
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state.DE++; mcycles = 2;;
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0x23: // INC HL
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state.HL++; mcycles = 2;;
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0x33: // INC SP
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state.SP++; mcycles = 2;;
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0x04: // INC B
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state.B++;
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state.zero = (state.B == 0);
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state.subtract = false;
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state.halfcarry = (state.B & 0x0F == 0);
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;
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0x14: // INC D
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state.D++;
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state.zero = (state.D == 0);
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state.subtract = false;
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state.halfcarry = (state.D & 0x0F == 0);
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;
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0x24: // INC H
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state.H++;
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state.zero = (state.H == 0);
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state.subtract = false;
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state.halfcarry = (state.H & 0x0F == 0);
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;
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0x34: // INC [HL]
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u8 data = bus->read8(state.HL);
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data++;
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bus->write8(state.HL, data);
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state.zero = (data == 0);
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state.subtract = false;
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state.halfcarry = (data & 0x0F == 0);
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mcycles = 3;
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;
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}
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}
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