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