public void Advance()
{
//advance the program by one cycle
//check if reached end of memory;
if (pc >= 4095)
{
Debug.WriteLine("ERR: reached end of memory");
}
else if (currentInstruction == "0000")
{
Debug.WriteLine("ERR: empty opcode");
}
//parse current instruction and set it to a variable
currentInstruction = String.Format("{0:X2}", memory[pc]) + String.Format("{0:X2}", memory[pc + 1]);
byteInstruction = memory[pc];
Debug.WriteLine("Instruction as byte: " + byteInstruction);
//parse x
x = Convert.ToInt16(Convert.ToString(currentInstruction[1]), 16);
//parsy y
y = Convert.ToInt16(Convert.ToString(currentInstruction[2]), 16);
//parse n
n = Convert.ToInt16(Convert.ToString(currentInstruction[3]), 16);
//parse kk
kk = Convert.ToInt16(currentInstruction.Substring(2), 16);
//parse nnn
nnn = Convert.ToInt16(currentInstruction.Substring(1), 16);
Debug.WriteLine($"\npc={pc}");
Debug.WriteLine($"The current instruction is:{currentInstruction} ");
//set drawflag to false by default
drawFlag = false;
//switch for all possible instructions
//TODO: replace this
switch (currentInstruction)
{
case "00E0":
Debug.WriteLine("00E0");
if (!usedInstructions.Contains("00E0"))
{
usedInstructions.Add("00E0");
}
Instructions.clr(this);
return;
case "00EE":
Debug.WriteLine("00EE");
if (!usedInstructions.Contains("00EE"))
{
usedInstructions.Add("00EE");
}
Instructions.ret(this);
return;
case var dummy when One_addr.IsMatch(dummy):
Debug.WriteLine("1nnn");
if (!usedInstructions.Contains("1nnn"))
{
usedInstructions.Add("1nnn");
}
Instructions.jmp(this);
return;
case var dummy when Two_addr.IsMatch(dummy):
Debug.WriteLine("2nnn");
if (!usedInstructions.Contains("2nnn"))
{
usedInstructions.Add("2nnn");
}
Instructions.call(this);
return;
case var dummy when Three.IsMatch(dummy):
Debug.WriteLine("3xkk");
if (!usedInstructions.Contains("3xkk"))
{
usedInstructions.Add("3xkk");
}
Instructions.skp_if_kk(this);
return;
case var dummy when Four.IsMatch(dummy):
Debug.WriteLine("4xkk");
if (!usedInstructions.Contains("4xkk"))
{
usedInstructions.Add("4xkk");
}
Instructions.skp_not_kk(this);
return;
case var dummy when Five.IsMatch(dummy):
Debug.WriteLine("5xy0");
if (!usedInstructions.Contains("5xy0"))
{
usedInstructions.Add("5xy0");
}
Instructions.skp_if_x_y(this);
return;
case var dummy when Six.IsMatch(dummy):
Debug.WriteLine("6xkk");
if (!usedInstructions.Contains("6xkk"))
{
usedInstructions.Add("6xkk");
}
Instructions.ld_vx_kk(this);
return;
case var dummy when Seven.IsMatch(dummy):
Debug.WriteLine("7xkk");
if (!usedInstructions.Contains("7xkk"))
{
usedInstructions.Add("7xkk");
}
Instructions.add_vx_kk(this);
return;
case var dummy when Eight_load.IsMatch(dummy):
Debug.WriteLine("8xy0");
if (!usedInstructions.Contains("8xy0"))
{
usedInstructions.Add("8xy0");
}
Instructions.ld_vx_vy(this);
return;
case var dummy when Eight_or.IsMatch(dummy):
Debug.WriteLine("8xy1");
if (!usedInstructions.Contains("8xy1"))
{
usedInstructions.Add("8xy1");
}
Instructions.or_vx_vy(this);
return;
case var dummy when Eight_and.IsMatch(dummy):
Debug.WriteLine("8xy2");
if (!usedInstructions.Contains("8xy2"))
{
usedInstructions.Add("8xy2");
}
Instructions.and_vx_vy(this);
return;
case var dummy when Eight_xor.IsMatch(dummy):
Debug.WriteLine("8xy3");
if (!usedInstructions.Contains("8xy3"))
{
usedInstructions.Add("8xy3");
}
Instructions.xor_vx_vy(this);
return;
case var dummy when Eight_add.IsMatch(dummy):
Debug.WriteLine("8xy4");
if (!usedInstructions.Contains("8xy4"))
{
usedInstructions.Add("8xy4");
}
Instructions.add_vx_vy(this);
return;
case var dummy when Eight_sub.IsMatch(dummy):
Debug.WriteLine("8xy5");
if (!usedInstructions.Contains("8xy5"))
{
usedInstructions.Add("8xy5");
}
Instructions.sub_vx_vy(this);
return;
case var dummy when Eight_shr.IsMatch(dummy):
Debug.WriteLine("8xy6");
if (!usedInstructions.Contains("8xy6"))
{
usedInstructions.Add("8xy6");
}
Instructions.shr_vx_vy(this);
return;
case var dummy when Eight_subn.IsMatch(dummy):
Debug.WriteLine("8xy7");
Instructions.subn_vy_vx(this);
return;
case var dummy when Eight_shl.IsMatch(dummy):
Debug.WriteLine("8xyE");
if (!usedInstructions.Contains("8xyE"))
{
usedInstructions.Add("8xyE");
}
Instructions.shl_vx_vy(this);
return;
case var dummy when Nine.IsMatch(dummy):
Debug.WriteLine("9xy0");
if (!usedInstructions.Contains("9xy0"))
{
usedInstructions.Add("9xy0");
}
Instructions.skp_not_equal(this);
return;
case var dummy when A_addr.IsMatch(dummy):
if (!usedInstructions.Contains("Annn"))
{
usedInstructions.Add("Annn");
}
Debug.WriteLine($"Annn where nnn = {currentInstruction.Substring(1, 3)}");
Instructions.ld_i_nnn(this);
return;
case var dummy when B_addr.IsMatch(dummy):
Debug.WriteLine("Bnnn");
if (!usedInstructions.Contains("Bnnn"))
{
usedInstructions.Add("Bnnn");
}
Instructions.jmp_v0_nnn(this);
return;
case var dummy when C_addr.IsMatch(dummy):
Debug.WriteLine("Cxkk");
if (!usedInstructions.Contains("Cxkk"))
{
usedInstructions.Add("Cxkk");
}
Instructions.ld_vx_rand(this);
return;
#region draw_func
//huomionarvoista:
// optimoinnin vuoksi voisi olla fiksua keksiä tapa vähentää type conversioneita
// huom. mahdolliset bugit jotka mainittu edellisissä kommenteissa
case var dummy when D_addr.IsMatch(dummy):
stopwatch.Start();
Debug.WriteLine("Dxyn");
if (!usedInstructions.Contains("Dxyn"))
{
usedInstructions.Add("Dxyn");
}
Instructions.drw(this);
stopwatch.Stop();
Debug.WriteLine($"draw function elapsed ms = {stopwatch.ElapsedMilliseconds}");
stopwatch.Reset();
break;
#endregion
case var dummy when E_skp.IsMatch(dummy):
Debug.WriteLine("Ex9E");
if (!usedInstructions.Contains("Ex9E"))
{
usedInstructions.Add("Ex9E");
}
Instructions.skp_vx(this);
return;
case var dummy when E_sknp.IsMatch(dummy):
Debug.WriteLine("ExA1");
if (!usedInstructions.Contains("ExA1"))
{
usedInstructions.Add("ExA1");
}
Instructions.sknp_vx(this);
return;
case var dummy when F_load_from_dt.IsMatch(dummy):
Debug.WriteLine("Fx07");
if (!usedInstructions.Contains("Fx07"))
{
usedInstructions.Add("Fx07");
}
Instructions.ld_vx_dt(this);
Debug.WriteLine($"registers[{x}] = {registers[x]}");
return;
case var dummy when F_load_key.IsMatch(dummy):
Debug.WriteLine("Fx0A");
if (!usedInstructions.Contains("Fx0A"))
{
usedInstructions.Add("Fx0");
}
Instructions.ld_vx_key(this);
return;
case var dummy when F_load_to_dt.IsMatch(dummy):
Debug.WriteLine("Fx15");
if (!usedInstructions.Contains("Fx15"))
{
usedInstructions.Add("Fx15");
}
Instructions.ld_dt_vx(this);
Debug.WriteLine($"delayTimer has been set to {delayTimer}");
return;
case var dummy when F_load_to_st.IsMatch(dummy):
Debug.WriteLine("Fx18");
if (!usedInstructions.Contains("Annn"))
{
usedInstructions.Add("Annn");
}
Instructions.ld_st_vx(this);
return;
case var dummy when Add_i_vx.IsMatch(dummy):
Debug.WriteLine("Fx1E");
if (!usedInstructions.Contains("Fx1E"))
{
usedInstructions.Add("Fx1E");
}
Instructions.add_i_vx(this);
return;
case var dummy when Load_f_vx.IsMatch(dummy):
Debug.WriteLine("Fx29");
if (!usedInstructions.Contains("Fx29"))
{
usedInstructions.Add("Fx29");
}
Instructions.ld_f_vx(this);
return;
case var dummy when Load_b_vx.IsMatch(dummy):
Debug.WriteLine("Fx33");
if (!usedInstructions.Contains("Fx33"))
{
usedInstructions.Add("Fx33");
}
Instructions.ld_bcd(this);
return;
case var dummy when Load_i_vx.IsMatch(dummy):
Debug.WriteLine("Fx55");
if (!usedInstructions.Contains("Fx55"))
{
usedInstructions.Add("Fx55");
}
Instructions.ld_i_vx(this);
return;
case var dummy when Load_vx_i.IsMatch(dummy):
Debug.WriteLine("Fx65");
if (!usedInstructions.Contains("Fx65"))
{
usedInstructions.Add("Fx65");
}
Instructions.ld_vx_i(this);
return;
default:
Debug.WriteLine("Unknown instruction");
pc += 2;
return;
}
}
