BizHawk/BizHawk.Emulation/CPUs/68000/Instructions/Supervisor.cs

163 lines
4.8 KiB
C#

using System;
namespace BizHawk.Emulation.CPUs.M68000
{
partial class MC68000
{
void MOVEtSR()
{
if (S == false)
throw new Exception("Write to SR when not in supervisor mode. supposed to trap or something...");
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
SR = ReadValueW(mode, reg);
PendingCycles -= 12 + EACyclesBW[mode, reg];
}
void MOVEtSR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
info.Mnemonic = "move";
info.Args = DisassembleValue(mode, reg, 2, ref pc) + ", SR";
info.Length = pc - info.PC;
}
void MOVEfSR()
{
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
WriteValueW(mode, reg, (short) SR);
PendingCycles -= (mode == 0) ? 6 : 8 + EACyclesBW[mode, reg];
}
void MOVEfSR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
info.Mnemonic = "move";
info.Args = "SR, " + DisassembleValue(mode, reg, 2, ref pc);
info.Length = pc - info.PC;
}
void MOVEUSP()
{
if (S == false)
throw new Exception("MOVE to USP when not supervisor. needs to trap");
int dir = (op >> 3) & 1;
int reg = op & 7;
if (dir == 0) usp = A[reg].s32;
else A[reg].s32 = usp;
PendingCycles -= 4;
}
void MOVEUSP_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
int dir = (op >> 3) & 1;
int reg = op & 7;
info.Mnemonic = "move";
info.Args = (dir == 0) ? ("A" + reg + ", USP") : ("USP, A" + reg);
info.Length = pc - info.PC;
}
void ANDI_SR()
{
if (S == false)
throw new Exception("trap!");
SR &= ReadWord(PC); PC += 2;
PendingCycles -= 20;
}
void ANDI_SR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
info.Mnemonic = "andi";
info.Args = DisassembleImmediate(2, ref pc) + ", SR";
info.Length = pc - info.PC;
}
void EORI_SR()
{
if (S == false)
throw new Exception("trap!");
SR ^= ReadWord(PC); PC += 2;
PendingCycles -= 20;
}
void EORI_SR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
info.Mnemonic = "eori";
info.Args = DisassembleImmediate(2, ref pc) + ", SR";
info.Length = pc - info.PC;
}
void ORI_SR()
{
if (S == false)
throw new Exception("trap!");
SR |= ReadWord(PC); PC += 2;
PendingCycles -= 20;
}
void ORI_SR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
info.Mnemonic = "ori";
info.Args = DisassembleImmediate(2, ref pc) + ", SR";
info.Length = pc - info.PC;
}
void MOVECCR()
{
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
ushort sr = (ushort) (SR & 0xFF00);
sr |= (byte)ReadValueB(mode, reg);
SR = (short)sr;
PendingCycles -= 12 + EACyclesBW[mode, reg];
}
void MOVECCR_Disasm(DisassemblyInfo info)
{
int pc = info.PC + 2;
int mode = (op >> 3) & 7;
int reg = (op >> 0) & 7;
info.Mnemonic = "move";
info.Args = DisassembleValue(mode, reg, 2, ref pc) + ", CCR";
info.Length = pc - info.PC;
}
void TRAP()
{
int vector = 32 + (op & 0x0F);
TrapVector(vector);
PendingCycles -= 26;
}
void TRAP_Disasm(DisassemblyInfo info)
{
info.Mnemonic = "trap";
info.Args = string.Format("${0:X}", op & 0xF);
}
void TrapVector(int vector)
{
short sr = (short)SR; // capture current SR.
S = true; // switch to supervisor mode, if not already in it.
A[7].s32 -= 4; // Push PC on stack
WriteLong(A[7].s32, PC);
A[7].s32 -= 2; // Push SR on stack
WriteWord(A[7].s32, sr);
PC = ReadLong(vector * 4); // Jump to vector
}
}
}